Classics in the History of Psychology

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Definitions Et - Ez

Posted July 2000

Eternal Generation [Lat. aeternus, perpetual, + genus, race]: Ger. ewige Schöpfung; Fr. génération éternelle; Ital. generazione externa. Eternal generation is a phrase indicating a certain view of the relation between the Father and the Son. Origen, in particular, contends for the eternal generation of the Son, as against Gnostic emanation and the like. According to this doctrine, the generation of the Son is a process that always continues. 'The Father did not beget his Son and let him go from himself, but always begets him.'

After the middle of the 2nd century, Christian thinkers began to employ the forms of the Alexandrian philosophy when they attempted to systematize the doctrines of their faith. The relation between the Deity and the Logos which the Alexandrians had pondered, offered some parallels, throwing light upon the difficult questions connected with the Trinity. The view is otherwise known as circumincession -- that is, mutual interpenetration. The subject is of philosophical interest as illustrating the influence of Graeco-oriental conceptions upon the statement of Christian dogma. (R.M.W.)

Eternity [Lat. aeternus, perpetual]: Ger. Ewigkeit; Fr. éternité; Ital. eternità. (1) Indefinite or endless duration in time; hence (2), as transcending the limits of temporal duration, that of which the conception includes timeless reality.

'Per eternitatem intelligo ipsam existentiam, quatenus ex sola rei aeternae definitione necessario sequi concipitur' (Spinoza, Ethica, i. def. 8). Schelling defines eternity as 'Sein in keiner Zeit' (Von Ich, 105), and Hegel as 'absolute Zeitlosigkeit': 'nur das Natürliche ist der Zeit unterthan, insofern es endlich ist; das Wahre dagegen, die Idee, der Geist, ist ewig' (Encyk., § 258). Cf. many citations in Eisler, Wörterb. d. philos. Begriffe, 'Ewigkeit.' (J.M.B.)

(3) In theology: this term is commonly used as the relative of TIME (q.v.), and therefore as implying the absence of limits which time imposes, or the transcendence of these limits.

The word has been predicated of creation. The problem of the eternity of creation raises all the fundamental questions connected with theism, especially those concerning the relation of God to the world. As the matter is not made the subject of special declarations in Scripture, it has ordinarily been set forth in a purely dogmatic manner. In other words, it has involved the adoption of fundamental and positive metaphysical positions, which usually have not been criticized, as philosophy understands this process. Theology, which posits Deity, may be said to solve the difficulty by asserting that time is eternally in God. Accordingly, everything is simultaneous as concerns God himself, but parts are so separable from each other that they can be 'revealed' in the succession which time implies.

Literature: DORNER, Syst. of Christ. Doctrine (Eng. trans.), ii. 21 f. (R.M.W.)

Eternity of God: Ger. Ewigkeit Gottes; Fr. éternité de Dieu; Ital. eternitàdi Dio. One of the attributes of God, deduced by some theologians from the ontological argument.

Philosophically, this subject raises the entire problem of transcendency and immanency; as, for example, in the question whether, although eternal, God can stand in the same relation to every event in time. Positing God, as theology does, it is possible to reply that he bears a different relation to different 'aeons,' and yet to maintain his unity with himself. But this solution is not open to philosophy, which must set out from the differences indicated, and, after pushing them to their extremest limits, attempt to reconcile them by strict speculative or rational methods.

Literature: DORNER, Syst. of Christ. Doctrine (Eng. trans.), i. 243 f. (R.M.W.)

Ether [Gr. aiqhr, the upper, purer air]: Ger. Aether; Fr. éther; Ital. etere. A medium or substance which, so far as we can yet determine, fills all space, and whose existence is inferred from the phenomena of radiance and electricity, the former being attributed to waves of the ether, the latter to a condition of it.

That ether penetrates transparent bodies is shown by the passage of light through them; it may therefore be supposed to penetrate and fill all bodies. No mechanical action has been detected between the ether and ordinary matter, since the rarest comets move through the ether without experiencing any appreciable resistance. Yet the heat-energy of bodies is communicated to the ether as radiance, a term which includes light and radiant heat; and if heat be a mode of molecular motion, the latter is communicated from matter to ether, though molar motion is not. Owing to these limitations of the action between matter and ether, the substance of the latter almost eludes investigation. (S.N.)

Ethical Emotion: see FEELING (ethical), and cf. SENTIMENT.

Ethical Judgment: see MORAL JUDGMENT.

Ethical Sense: see MORAL SENSE.

Ethical Theories: Ger. ethische Theorien; Fr. théories de morale; Ital. teorie morali (or di morale). Theories concerning the moral value of character and conduct; especially theories which attempt an explanation of ultimate practical worth.

There are two main sources from which ethical theories are derived: (1) direct reflection on actual conduct and its perplexities; (2) application to conduct of general philosophical theory. Ethical doctrine is almost always drawn from both sources; but the predominance of one or other may determine the nature of an ethical theory. In any society the earliest ethical doctrine is usually derived from the former source. This is seen in the early ethical speculation of Greece. The ethical reflections of the Pre-Socratic philosophers have usually the slightest, if any, connection with their speculations concerning the ultimate nature of reality (Heraclitus and Pythagoras being partial exceptions); and the beginning of scientific morality in Socrates is expressly dissociated from any theory of the nature of the world. On the other hand, the new view of God and man introduced by Christianity, the Kantian analysis of experience, and the Darwinian theory of natural selection are instances of theoretical views which have had profound consequences for ethical doctrine. But this distinction of the two different sources of ethical doctrine does not adequately characterize (as Ziegler thinks) the difference between the great movements of ethical thought. Greek ethics, for example, becomes a metaphysical theory with Plato; and, in general, the great philosophical thinkers have elaborated their ethical and theoretical doctrines in close connection.

It thus happens that the distinctive marks of the leading ethical theories cannot be given apart from an explanation of the general philosophical position to which they belong. This is specially the case with such writers as Plato, and in modern times Kant, Fichte, Hegel, Schopenhauer, and Spencer.

The main grounds of distinction between ethical theories are: (1) Their different modes of conceiving the moral ideal or summum bonum. (2) Different views concerning the way in which the human consciousness apprehends the bindingness of moral rules or the intrinsic worth of moral ideals -- whether by some kind of immediate knowledge (Intuitionism) or by experience of the tendency of actions to bring about results judged to be good (Empiricism, and, when the continuity of the experience of the race is emphasized, Evolutionism). Both intuitionism and, to some extent, evolutionism are frequently understood as signifying special views of the ideal or end. (3) Differences concerning the nature of moral obligation, or the relation of the moral principle to man's will, lead to the distinction of autonomous and heteronomous systems. The former find the moral law, as well as the motive for conforming to it, in man's own nature -- generally in his nature as rational; the latter derive the law, as distinct from the motive for conforming to it, from some external authority, such as the will of God, or the law of society; while Kant includes as heteronomous all theories which admit as moral motives any other inducements than pure reverence for the moral law, which is at the same time practical reason. (4) This last point indicates, however, a further ground of distinction -- regarding the motives which can be recognized in the moral life. Morality may be so defined, as it was by the Stoics and by Kant, as to dissociate entirely the moral or rational from the emotional life: to this view the term Rigorism may appropriately be applied. On the other hand, the character of an ethical doctrine may be determined by the emphasis laid on a special aspect of the emotional life, or a special kind of motives, as in the position given to sympathy in the moral theory of Adam Smith, and afterwards of Schopenhauer. Other grounds of distinction between ethical theories sometimes given, as that of the kind of objects to which moral action has regard (whether oneself simply, or other persons, or communities), may be better dealt with in subordination to the first ground of distinction.

Premising that the ethical theories of the great systematic thinkers (idealistic or naturalistic) fit but badly into any independent classification, and restricting attention to the two first grounds of distinction given above, as the most important, we may distinguish (1) theories which depend chiefly on a special view of the ideal, end, or summum bonum: (a) the various forms of Hedonism, which agree in maintaining that pleasant feeling is the ultimate standard of moral value; (b) the doctrines of perfection and SELF-REALIZATION (q.v.), according to which the moral ideal is a perfection of character, or the complete and harmonious development of personal capacities; (2) theories which start from the mode in which morality is apprehended or realized: (c) the various forms of Intuitionism, aesthetic or perceptional and rational; (d) the various forms of Empiricism, which when not simply hedonistic, and when it does not accept its rules of duty from some external authority (as Hobbes proposes to accept them from the sovereign), usually connects itself with some theory of evolution.

(a) According to hedonism, the moral value of conduct depends upon its tendency to increase pleasure and diminish pain. This is common to all forms of the theory from Aristippus of Cyrene, the 'imperfect Socratic,' onwards. The most important advocate and systematizer of this doctrine was Epicurus, who emphasized the value not of momentary feelings, but of a pleasant or happy life, and the necessity therefore of a mind free from disturbance and care (see EPICUREANISM). For him the ideal life is one of tranquillity -- of quiet living and freedom from pain. But it has to be pointed out that a life of excitement -- of many and varied pleasures, sufficiently numerous and intense to make up for considerable pains -- is an equally legitimate ideal for the hedonist. And only a calculus of pleasures and pains and of the probabilities of life could decide which ideal is more desirable, hedonistically, for any individual agent. In modern times hedonism has divided into two opposed theories, egoistic and universalistic, according as the moral end is held to be the agent's own greatest pleasure, or that of mankind (or even sentient beings) generally (see GREATEST HAPPINESS, EGOISM, and UTILITARIANISM). To the latter the name Utilitarianism was given by J. S. Mill. The term ALTRUISM (q.v.), used by Comte, emphasizes the reference to other individuals rather than to communities; but as only individuals are conscious of pleasure and pain, this does not distinguish the theory from utilitarianism. The real distinction (using both terms hedonistically) is that altruism does, and utilitarianism does not, deny moral value to the pleasure of self. Mill's important modifications of the hedonistic doctrine are, first, his emphasis on the importance of permanent sources of interest over disconnected pleasures -- a point further elaborated by Sidgwick; and, secondly, his distinction of pleasures in kind or quality, and contention that (e.g.) intellectual pleasures are of higher moral value than sensuous pleasures, quite independently of any superior intensity, purity, fruitfulness, or other quantitative distinctions. But this clearly makes not pleasure itself, but that which distinguishes the higher pleasure from the lower the ultimate standard of value, and is accordingly inconsistent with the hedonistic principle.

(b) The doctrines of PERFECTION (q.v.), and SELF-REALIZATION (q.v.), in so far as they are distinct from the more purely rationalistic or intuitional forms of idealistic ethics, may be said to date from Aristotle, who maintained that the chief good consisted in an activity in accordance with the highest virtue (see EUDAIMONIA). The theories which may be grouped under this head are much more divergent from one another in nature, and often less clear in statement, than are the different hedonistic theories. The nature of the perfection which is to be attained, or of the self which is to be realized, can only be expounded after a philosophical inquiry; and the ethical doctrines of Spinoza and Leibnitz, Fichte and Hegel, might all be included under this head. The form in which the notion of self-realization appears in contemporary ethics is largely due to T. H. Green, who lays special stress both on the spiritual or rational and on the social nature of the self.

(c) According to the intuitional view of ethics the end of conduct consists in the correspondence of voluntary activity with certain intuitively recognized moral rules. This view has its historical antecedent in the Stoic doctrine of laws of nature, belonging to the reason of the universe and apprehended by the consubstantial reason of man. The same doctrine formulated in theological terms led to the dominant systems of mediaeval ethics and their related doctrines of SYNDERESIS (q.v.) and CONSCIENCE (q.v.). In the beginning of English philosophy these moral first principles were regarded as principles of the sensus communis by Herbert of Cherbury; and he may accordingly be held to be the founder of the English school of intuitional or common-sense morality. But in the English moralists of the 18th century this immediate apprehension of moral value was interpreted as aesthetic or perceptional rather than rational by Shaftesbury and Hutcheson. Hutcheson elaborated the doctrine (derived from Shaftesbury) of a moral sense -- 'a natural and immediate determination to approve certain affections, and actions consequent upon them, or a natural sense of immediate excellence in them' -- and combined this view with the utilitarian criterion of the distinction between right and wrong. On the other hand, the rational or 'dogmatic' interpretation of the moral faculty was worked out anew by Samuel Clarke, Price, and Reid. The 'philosophical' intuitionism of Kant reaches a complete synthesis of moral law founded upon a criticism of the reason. The speculative theories of ethics which have resulted from Kant's criticism tend rather to the perfectionist than to the traditional intuitional ideal.

(d) The theory of evolution, which traces the development both of moral conduct and of moral ideas, was, when first applied to ethics, associated with the hedonistic theory, but was soon found to lead to modifications of that theory (as by Spencer); while other writers (of whom L. Stephen was one of the earliest) have attempted a more specifically evolutionist ethics. By these writers some such conception as social vitality has often been taken as the ethical ideal; but the most valuable part of the work done by the evolutionist moralists has been (as was natural) in tracing the genesis and progress of morality both historically and in the individual, rather than in independent contributions towards the solution of the question of the ultimate conditions of moral value (however, cf. WORTH).

Literature: hedonistic theories are chiefly represented by GASSENDI, De vita, moribus et doctrina Epicuri (1647); HOBBES, Elements of Law, Human Nature (1640), and Leviathan (1651); LOCKE, Essay concerning Human Understanding (1690); HUTCHESON, Syst. of Mor. Philos. (1755) (who adopts greatest happiness as the moral standard); HUME, Human Nature, Bk. III (1740), and Princ. of Mor. (1751); LAMETTRIE, L'art de jouir (1751); HELVETIUS, De l'esprit (1758); HOLBACK, Syst. de la Nature (1770), and Éléments de la morale universelle (1776); PALEY, Mor. and Polit. Philos. (1785); BENTHAM, Princ. of Mor. and Legisl. (1789); J. S. MILL, Utilitarianism (1861); H. SIDGWICK, Meth. of Ethics (1874); SPENCER, Princ. of Ethics (1879-93); GIZYCKI, Grundzüge d. Mor. (1883), and Mor. Philos. (1888). Cf. J. WATSON, Hedonistic Theories (1895).

Divergent expressions of the perfectionist ideal, combined with the hedonistic factors, are to be found in CUMBERLAND, De legibus naturae (1672); SPINOZA, Ethica (1677); LEIBNITZ, Théodicée (1710), Nouveaux Essais (written 1704), and Principes de la Nature et de la Grâce (1714). Modern theories of self-realization influenced by FICHTE (Syst. d. Sittenlehre, 1798), and more precisely by HEGEL (Philos. des Rechts, 1821), are represented in English chiefly by F. H. BRADLEY (Ethical Studies, 1876) and T. H. GREEN (Prolegomena to Ethics, 1882).

The chief moral sense writers were SHAFTESBURY, Inquiry concerning Virtue and Merit (1699); HUTCHESON, Inquiry into the Original of our Ideas of Beauty and Virtue (1729); Essay on the Passions, with Illustrations on the Moral Sense (1728) and Syst. of Mor. Philos. (1755). The ethics of sympathy was set forth by ADAM SMITH, Mor. Sent. (1759), and in more recent times by SCHOPENHAUER, Die beiden Grundprobleme d. Moral (1841). The intellectualist tradition of intuitionism is represented by CUDWORTH, Eternal and Immutable Morality (publ. posthumously, 1731); S. CLARKE, Boyle Lectures (1705); J. BUTLER, the ethical doctrine of whose Sermons (1726) is allied to that of Shaftesbury, and who approaches the intellectualist view in his Diss. on Virtue (1736); R. PRICE, Principal Questions and Difficulties of Morals (1757); T. REID, Active Powers (1788). Modern intuitional ethics has been modified by KANT, Grundlegung d. Met. d. Sitten (1785); Krit. d. prakt. Vernunft (1788). It is represented chiefly by WHEWELL, Elements of Morality (1841); CALDERWOOD, Handb. of Mor. Philos. (1874); RICKABY, Mor. Philos. (1889). MARTINEAU'S Types of Ethical Theory (1885) is the most brilliant and original outcome of recent intuitional doctrine.

The influence of the theory of evolution upon ethics is shown chiefly in SIMCOX, Natural Law (1877); SPENCER, Princ. of Ethics (1879-93); L. STEPHEN, Science of Ethics (1882); ROLPH, Biologische Probleme (1882); HÖFFDING, Grundlage d. human. Ethik (Ger. trans., 1880), and Ethik (Ger. trans., 1888); S. ALEXANDER, Moral Order and Progress (1889); WUNDT, Ethik (1886); SIMMEL, Einleit. in die Moralwissenschaft (1892-3); BALDWIN, Social and Eth. Interpret. (1897). SORLEY, Ethics of Naturalism (1885), and HUXLEY, Evolution and Ethics (Romanes Lecture, 1893), are criticisms of the evolution theory of ethics. (W.R.S., H.S.)

Ethics [Gr. ta hqika, from hqoV, used by Aristotle in the sense of character and disposition, but having originally the same reference to the externals of custom or usage as eqoV, of which it is a lengthened form. The term moralis was introduced by Cicero as an equivalent of Aristotle's hqikoV]: Ger. Ethik (Sittenlehre); Fr. morale, éthique; Ital. etica. The science of the ideal in human character and conduct.

The terms ethics, moral science, and moral philosophy are used almost synonymously. No distinction can be drawn between 'ethical' and 'moral,' except that the latter term is somewhat more commonly used of the facts and judgments with which the science deals. Ethics has sometimes been defined as the 'art' of conduct, just as logic has been called the art of thinking. But the former definition can be defended as little as the latter. According to the older use of the terms, an art has to do with production, not with practice or conduct. Further, ethics does not teach the doing of good, but knowledge of the nature and conditions of goodness. This knowledge may be applied to practice, but it does not necessarily imply the condition of will required for good conduct. Ethics has, however, to do not merely with actual conduct, but with right or good conduct, and accordingly with an ideal from which rules may be laid down for actual conduct, so that it may be called a normative science.

Whether it should be regarded as a science or as a branch of philosophy is a more difficult question: partly owing to the uncertainty which  attaches to the distinction between science and philosophy, partly owing to the nature of ethical inquiry itself. It has to do with the facts of conduct as displayed in individual experience and in the social order and development, and thus deals with a more or less well-defined group of phenomena. But it is concerned not merely with the order of occurrence of these facts, but with their relation to norms or rules, in virtue of which relation the facts of conduct are judged good or bad, right or wrong. These norms or rules, which may appear almost disconnectedly in ordinary consciousness, admit of inner relation and justification when shown to result from an ideal which has validity as a standard of moral goodness or moral value.

It is in determining the ideal or moral end that ethics requires a philosophical rather than a merely scientific mode of treatment. The attempts to decide this question independently of general philosophy or of metaphysics are chiefly the following: (a) testing the applicability to conduct of the various ends which are prima facie reasonable -- a method which may leave the inquirer with two or more competing systems, and which besides seems to attribute too great importance to the precise applicability of the end to the complex and varying conditions of life, while the reasonable ends to be considered can hardly be exhaustively discovered without an inquiry into the conditions of self-conscious activity and its relation to reality; (b) appealing to the individual consciousness of what is desired, as was done by J. S. Mill in the interests of his happiness-theory; (c) testing the fitness of conduct to promote social order and progress. At any given stage of social development the conditions of social order may be laid down from an analysis of that order and examination of the conduct fitted to maintain it; but the social order is itself in constant process of development, the direction of which is partly determined by the moral ideals of the members of the society. And at any given stage of the development of an individual consciousness, its content may be systematically elaborated so as to give an account of the duties it holds binding, or of the ends regarded by it as desirable; but his content also is variable. And a standard is needed to justify the obligatoriness of these duties or the value of these ends. Thus neither the sociological nor the psychological method seems sufficient to determine the ideal of goodness for conduct. Cf. END (moral).

We accordingly find that, in nearly all cases, ethical doctrines are closely connected with the general philosophical point of view of a thinker. This does not hold true of many of the English moralists of the 18th century, nor, among systematic philosophers, of Herbart; but the contemporary moralists who treat ethics simply as a science are often influenced by a naturalistic or an agnostic interpretation of the world and of life.

The fundamental conceptions of ethics are: (1) the ideal or end, which is the standard of goodness in character and conduct. The terms right, duty, virtue, value are sometimes used in place of this; but, more correctly, they signify respectively the agreement of conduct with the rule or law resulting from this standard, the relation of the law as authoritative for a will which may nevertheless disobey the law, the organization of right conduct into habits of acting, the degree of approximation to the ideal. (2) Freedom, or the power of conforming to the law or realizing the ideal belonging to human conscious activity. It is only because man is able not only to apprehend a moral law or ideal, but consciously to guide his conduct by it, in presence of competing inducements, that he is a moral being. Ethics has accordingly to investigate the meaning and possibility, as well as the implications and applications of these conceptions. And in this department of its inquiry it is not independent of metaphysics. But these questions are connected with other ethical questions of a more specifically scientific character: e.g. the psychological nature of moral motives, moral ideas, and moral habits (or virtues); the system of duties and of virtues, and their connection with social institutions and customs. With regard to these questions, the theory of evolution has had a most important bearing upon ethics, bringing out the history of moral conduct and moral ideas in connection with one another and with social institutions. Cf. ETHICAL THEORIES.

Literature: in addition to the works cited under ETHICAL THEORIES, the following may be cited: SCHLEIERMACHER, Syst. d. Sittenlehre (1835); RENOUVIER, Sci. de la morale (1869); HERBART, Prakt. Philos. (1808); STEINTHAL, Ethik (1885); NAHLOWSKY, Allg. Ethik (1885); E. VON HARTMANN, Das sittliche Bewusstsein (1879); PAULSEN, Syst. of Ethics (Eng. trans., 1899); GUYAU, Esquisse d'une Morale sans Obligation (1885); S. H. HODGSON, Met. of Experience, iii (1899); the important elaborations of ethics as the theory of values by MEINONG, Psychologischethische Untersuchungen z. Werttheorie (1894), and v. EHRENFELS, Syst. d. Wert-theorie (1897-8); and the introductory works: J. H. MUIRHEAD, Elements of Ethics (1892); J. DEWEY, Outlines of Ethics (1891); J. S. MACKENZIE, Manual of Ethics (1893); J. SETH, Study of Ethical Principles (1894). Among the more important histories of ethics are SCHLEIERMACHER, Krit. d. bisherigen Sittenlehre (1803); VORLÄNDER, Gesch. d. Moral-, Rechts- u. Staats-Lehre (1885); I. H. FICHTE, Syst. d. Ethik (1850); SCHMIDT, Ethik d. alten Griechen (1882); ZIEGLER, Ethik d. alten Griechen u. Römer (1881), and Christl. Ethik (2nd ed., 1892); GASS, Gesch. d. christl. Ethik (1881); JODL, Gesch. d. Ethik in d. neuern Philos. (1882-9); FOUILLÉE, Syst. de Mor. anglaise contemporains (1883); GUYAU, Mor. anglaise contemporaine (2nd ed., 1885); and the admirable short Outlines of the History of Ethics by H. SIDGWICK (3rd ed., 1892). See also ETHICS (Christian). (W.R.S., H.S.)

Ethics (Christian). (1) A systematic scientific ingathering and articulation of the doctrines of Christianity in their bearing upon individual conduct; and (2) an exposition of the Christian ethos or general Christian attitude towards life and society.

In its root sense, the term ethics does not refer merely to conduct, but also to a community or agreement amongst larger or smaller groups of men in approving and appropriating or disapproving certain modes of life and ideals of character. This is best indicated, possibly, in the contrasts presented by different modern nationalists, or by different sections of the Christian community, or even between different ranks of society in the same state. Theologically viewed, Christian ethics is the practical aspect of the considerations which dogmatics sets forth theoretically.

A due and full statement of the contents of Christian ethics would consist of the following: (1) an account of the relation of Christian ethics to other disciplines -- to metaphysics, ethics proper and moral philosophy, psychology, theology, sociology, and the like; (2) a discussion of the Christian ideal in its religio-historical, formal, and material aspects; (3) an outline of Christian duties directly deducible from the foregoing; (4) following from all these, what might be called a Christian sociology -- dealing with marriage and the family, the state, and so on. Some would add to this a discussion of the Church, viewed as the Christian community.

Literature: DORNER, Syst. of Christ. Ethics (Eng. trans.), where the literature of special topics is fully given; NEWMAN SMYTH, Christ. Ethics; MAURICE, The Epistles of St. John; KNIGHT, The Christ. Ethic; KÖSTLIN, Christl. Ethik. (R.M.W.)

Ethnography (1), Ethnology (2) [(1) Gr. eqnoV, a people, + grafein, to write; (2) eqnoV, people, + logoV, discourse]: Ger. Ethnographie, Ethnologie (Völkerkunde); Fr. ethnographie, ethnologie; Ital. etnografia, etnologia. Ethnography and ethnology form two large divisions of ANTHROPOLOGY (q.v.), and relate to the study of human groups and organizations -- hordes, clans, races, peoples, nations.

In distinction from one another, ethnography includes the descriptive, external account of particular groups of men and their status, occupations, and institutions; while ethnology presents the explanatory and investigative study of such racial and cultural relations in general. The two divisions thus deal largely with the same materials, many investigations contributing almost equally to both; and differ mainly as the preparatory collection, arrangement, and description of the nature and occurrence of any phenomena differ from the systematic and interpretative study of the causes and influences affecting it and its correlated phenomena.

Of prime importance to these sciences is everything that relates to the determination of origins, migrations, distributions, variations, and correlations of the several races and peoples. Apart from the problems which concern the descent of man and his antiquity, the fundamental ethnological problems relate (a) to the specific unity of the human species, whether originally derived from one single parent stock (the monogenistic view) or from several (the polygenistic view); (b) to the varietal diversity of man, i.e. the fundamental type varieties of the human race (Hominidae); (c) to the classification of these in suitable ethnical groups (Mongolian, Caucasian, American, Ethiopian, or similar classification); (d) to the determination of the migrations and distribution of such races and their relation to one another. In this investigation the distinction between prehistoric and historic is of prime importance; prehistoric evidence being largely of the form of skeletal remains of man and relics of primitive industries, while in historic times these are in themselves more complete, and are supplemented by written and oral traditions and a wealth of suggestive details in regard to institutions and organizations. The unity and fundamental varieties of the human race must be largely decided upon the evidence of the physical character of human remains -- i.e. such evidence is somatological or physical, while the further history of human groups, although both physical and mental, is largely the latter. It is to be derived from the evidence of man's sociological institutions, the direction and nature of his psychological development, his language, his arts and sciences, his religion. The detailed problems of ethnology thus relate to the racial history, the distribution and evolution of special physical traits (colour of skin, proportion of head, &c.), or of particular groups of customs and institutions. This latter division is particularly fertile, and constitutes a large portion of ethnological literature. Language, written and spoken, groups of customs and traditions, myths and beliefs, family relationships and tribal organizations, music and the dance, the arts of the field and the loom, of the worker of human habitations, and transportation by land and sea; these and many more may be cited to indicate the scope of special ethnological studies. Such descriptive details, when collected in regard to a single people or group, as well as the comprehensive description in all these respects of the physical and mental status of a special people or group, may properly be spoken of as ethnographic. Such ethnographic literature, particularly as accumulated by travellers in modern times, is most extensive.

Literature: general introductory works to the study of Ethnology are: KEANE, Ethnology (1897), 442; TOPINARD, Anthropology (1878), 548; QUATREFAGES, The Human Species (1879), 498; BRINTON, Races and Peoples (1890), 313; MORSELLI, Antropol. generale (1889-91). Also see ANTHROPOLOGY. Consult in regard to the status of special literature the article Ethnography in Encyc. Brit. (9th ed.), ad fin. (J.J.)

Ethology [Gr. eqoV, custom, + logoV, discourse]: Ger. Ethologie, Charakterologie (Bahnsen); Fr. éthologie; Ital. etologia. The science of the formation of human character, whether of individuals or of groups of men.

The term is used by J. S. Mill, who regards ethology as a deductive science, whose 'principles are properly the middle principles, the axiomata media (as Bacon would have said) of the science of mind; as distinguished, on the one hand, from the empirical laws resulting from simple observation, and, on the other, from the highest generalizations.' He calls it 'the Exact Science of Human Nature' for its truths are not, like the empirical laws which depend on them, approximate generalizations, but real laws' -- although 'hypothetical only,' and affirming 'tendencies, not facts.' Other usages are those of Wundt and Bailey.

Literature: J. S. MILL, Syst. of Logic, Bk. VI. chap. v; WUNDT, Logik (2nd ed.), ii. 2. 369; J. WARD, in Int. J. of Ethics, i. 446 ff.; T. P. BAILEY, Ethology (1899), and Bibliog. Refs. in Ethology (1899) (W.R.S.- J.M.B.)

Ethos [Gr.]: Ger. Ethos; Fr. moeurs; Ital. costume morale. Moral disposition or character; especially the prevalent moral disposition of a community, as shown in its customary behaviour.

The reference to the internal traits of disposition, instead of to external results, distinguishes ethos from CUSTOM (q.v.), although the Greek term hqoV (of which it is a transliteration) had originally the same reference to external conditions as the related term eqoV. Cf. Wundt, Ethik, Pt. I. chap. i. (W.R.S.)

Etiology [Gr. aitia, cause, + logoV, discourse]: Ger. Ätiologie; Fr. étiologie; Ital. etiologia. (1) In philosophy: the science of CAUSE AND EFFECT (q.v.).

(2) In medicine: the science of the causes of organic and mental disease. (E.M.)

In biology: that branch of biology which deals with the origin and mode of development of organic beings.

Introduced by Huxley (Anatomy of Invertebrate Animals, Introd. 35, 1877), but not in general use. (C.LL.M.- J.M.B.)

Etymology [Gr. etumoV, true, + logoV, discourse]: Ger. Etymologie; Fr. étymologie; Ital. etimologia. The history of a word, so far as it can be traced towards its origin, as regards both its form and its signification; that department of scientific grammar which concerns itself with the determination of such word-history.

Among the ancient Greeks, etymology was used of the search for the etnmon, the real and essential meaning of a word, a search conducted in the belief that words, as necessarily connected with the things they denoted, held within them the secret of the inner nature of things and ideas. The etymology of modern scientific grammar seeks to discover the earlier history of the forms and values of words, using the comparison of cognate languages and dialects where direct tradition fails. It includes the cases where a word can be followed back into the territory of another language from which it has been borrowed. The etymology of a word is not directly applicable in determining the proper form or use of that word in current speech. The earlier meaning is no 'truer' than the later. It shows, however, how the word has come to be what it is, and affords a basis of judgment in estimating the orbit and axis of its value.

The best illustration of modern etymological work will be found in Murray's New English Dictionary (1884-), and Kluge's Etymol. Wörterbuch der deutschen Sprache (6th ed., 1898-). (B.I.W.)

Eubulides. Lived in the 4th century B.C. Born at Miletus, he became the pupil of Euclid of Megara, and a member of the Megarian school. He and Alexinus are mentioned as inventors of new fallacies in the school. They opposed Aristotle.

Eucharist [Gr. en, well, + cariV, favour, grace]: Ger. heiliges Abendmahl, Eucharistie; Fr. sainte cène, eucharistie; Ital. Eucharistia. One of the several names given to the sacrament of the Lord's Supper.

The sacrament of the Eucharist did not reach its complete development in the Latin Church till the 6th century; and after the Reformation very divergent views emerged with regard to it. Without going into the numerous details connected with the subject, these positions may be very briefly summarized as follows: (1) The doctrine of the real presence. The whole substance of the bread is converted into the body, and the whole substance of the wine into the blood, of Christ, as the Council of Trent decreed. This, and the Luteran doctrine, raise the curious problem of the ubiquity of Christ. (2) The doctrine of the virtual presence, which implies that the Eucharist is the only medium through which Christ confers the benefits of his atonement upon men. (3) The doctrine of the figurative presence, according to which the rite and the elements are memorials of Christ's death till he come. Philosophy of religion would distinguish between the rite and the elements, while a distinctively Christian philosophy of religion would contend for the spiritual presence of Christ in the former, but hold the latter for mere symbols. Obviously, the meaning of the spiritual presence here advocated admits of widely divergent interpretations.

Literature: DORNER, Syst. of Christ. Doctrine (Eng. trans.), iv. 305 f., where the literature is fully given. (R.M.W.)

Euclid of Alexandria. Lived about 300 B.C. in Alexandria, and taught mathematics there in the reign of Ptolemy I (Soter), who died about 282 B.C. His Elements of Geometry is the only ancient system of geometry extant. It was a standard work for 2,000 years. He is called 'the father of geometry,' which is termed 'Euclidian' from him.

Euclid of Megara. Greek philosophy, who lived about 400 B.C. Pupil of Socrates, and said to have seen him die. After that event (399 B.C.) he returned to Megara and founded a famous school of Megarians, taking his doctrine in part from both the Eleatics and Socrates.

Euclidian Space. The 'ordinary' or tri-dimensional SPACE (q.v.) of the Euclidian geometry. (J.M.B.)

Eudaemonism [Gr. eudaimonia, happiness]: Ger. Eudämonismus; Fr. eudémonisme; Ital. eudemonismo. The theory that happiness is the chief good for man, or the ethical END (q.v.) for his conduct.

The term is derived from EUDAIMONIA (q.v.), which was first used as the leading conception of ethics by Aristotle. The eudaemonism of Aristotle was a theory which placed the chief good in an active life in accordance with the highest excellence or virtue. But a different view, which found the essential element of this highest life in the feeling of pleasure, found its way into the school of Aristotle as early as the Eudemian Ethics formerly ascribed to Aristotle himself, and included in the Corpus Aristotelicum. The hedonistic interpretation of what constitutes eudaimonia, or happy life, was urged with confidence by Epicurus and his followers; and the traditional renderings of the word into other languages have encouraged this meaning. Thus the term eudaemonism, in modern philosophy, is almost universally used for the ethical theory which puts forward happiness (in the sense of pleasure and freedom from pain) as the end of life. The term eudaemonism (happiness-theory) becomes in this way indistinguishable in meaning from hedonism (pleasure-theory). The distinction drawn by Külpe (Einleitung in die Philos., § 14) that hedonism takes corporeal pleasure for the end, and eudaemonism mental pleasure, is not in accordance with historical usage, and would leave no important theories to be described as hedonistic.

The character and practical value of the theory vary greatly according to the sources (sensuous, intellectual, aesthetic, social, or conscientious feelings) to which happiness is regarded as mainly due, and according to whether the agent is bidden to regard his own happiness only or to promote that of others. Kant is thus mistaken in asserting that 'the eudaemonist is he who sets the highest determinant of his will in utility and his own happiness. All eudaemonists are therefore practical egoists' (Anthrop., init.). The vast difference between the egoistic and universalistic forms of theory has been set forth, especially, by J. S. Mill (Utilitarianism) and H. Sidgwick (Meth. of Ethics). Owing to the variance between the Aristotelian meaning of eudaimonia and the modern 'happiness,' stricter writers prefer the term hedonism to eudaemonism, e.g. Sidgwick (as above); on the other side, see Pfleiderer, Zur Ehrenrettung des Eudämonismus (1879). The term is used in its Aristotelian sense by J. Seth, Ethical Principles (1894). (W.R.S.)

Eudaimonia [Gr. eudaimonia, commonly rendered happiness]: Ger. Glückseligkeit; Fr. bonheur; Ital. felicità. Well-being or welfare. See EUDAEMONISM.

The word means literally the condition of being guided or favoured by a good genius, and hence good forture or happiness. Plato speaks of eudaimonia as the end or goal of the political art (Euthyd., 291 B); and the term is adopted by Aristotle as used both by thinkers and by plain men as an expression for the highest attainable good of man. As such it becomes the central conception of his ethical system, and receives a special meaning as the result of his analysis. He holds it to be an active condition which cannot be analysed into any succession or sum of pleasures, though pleasures accompanies its realization. It is a well-being which consists in well-doing -- an activity (energeia) in accordance with the highest excellence (areth, or virtue) attainable by man (Eth. N., I. iv. 2, &c.); and his highest conception of this activity was a life of pure speculation, although he did not maintain that such a life was attainable by man. The Aristotelian or Peripatetic school, however, soon tended to an interpretation of eudaimonia in terms of pleasure (hdonh), and Epicurus enforced the doctrine that eudaimonia was pleasure. In this way the Latin equivalent of eudaimnia (felicitas), as well as its traditional renderings in modern languages, have a hedonistic meaning which is alien to the Aristotelian conception of eudaimonia (W.R.S.)

Eudemus. A Greek, native of Rhodes, pupil of Aristotle. He is signalized by the Eudemian Ethics, formerly attributed to Aristotle. Other fragments of his are extant. See PERIPATETICS.

Eusebians: Ger. Eusebianer; Fr. Eusébiens; Ital. Eusebiani. One of the great parties at the Council of Nicaea. They were so called from their leader, Eusebius, bishop of Caesarea. The Lucianists (Arians) and the Alexandrians were the other parties. The Eusebians occupied the middle position, but stood much nearer to the Lucianists than to the Alexandrians; and they might easily have turned the scale in favour of Arian views, had their tactics been more adroit.

Literature: GWATKIN, Studies of Arianism; HARNACK, Hist. of Dogma (Eng. trans.), iv. 51 f. (R.M.W.)

Eutychianism: Ger. Eutychianismus; Fr. Eutychianisme; Ital. Eutichianismo. So called from Eutyches, who was head of a monastery near Constantinople. His doctrine was fully formulated 448-51 A.D. It is another of the many attempts to solve the problem of the two natures -- divine and human -- in a single person, Christ. It consists essentially in an emphasis upon the unity of personality to the obliteration of the distinction of natures. The human nature is deified by being absorbed into the divine. Hence, in opposition to NESTORIANISM (q.v.), Eutychianism teaches that God was born, was tempted, suffered, and died.

Literature: MANSI, Sacrorum Conciliorum nova et amplissima Collectio, ix. 674 f.; MARTIN, Le Pseudo-Synode d'Éphèse; HARNACK, Hist. of Dogma (Eng. trans.), iv. 197 f. (R.M.W.)

Evangel: see GOSPEL.

Event [Lat. eventus, from evenire, to happen]: Ger. Ereigniss; Fr. évènement; Ital. evento, avvenimento. Any change in the world of FACT (q.v.).

The notion of event covers objective phenomenal changes and sequences of all sorts. The common usage makes the event a matter of time; and this is emphasized by the usage according to which events are the subject-matter of history, that is, each event is in relation to a series of happenings in time. Whether events may take place out of time would seem to depend upon one's general theory of time in relation to reality. (J.M.B.)

Everett, Charles Carroll. (1829-1900.) American writer on philosophy and theology. Born at Brunswick, Maine, and died at Cambridge, Mass. Graduated from Bowdoin College in 1850, studied at Harvard and Berlin Universities, was Unitarian clergyman, became professor of theology in Harvard Divinity School in 1859, and dean of that institution in 1878.

Evidence and Evident [Lat. e + videre, to see]: Ger. Evidenz, evident, einleuchtend; Fr. évidence, évident; Ital. evidenza, evidente. As used in logic, the term signifies the propositions or assertions of fact from which a conclusion is taken to follow. Distinctions in such evidence concern the matter involved, for evidence is equivalent to the reasons, not the causes, of a judgment, and thus has always an objective or universal significance.

The common division of evidence resolves itself into (a) the intuitive and demonstrative, and (b) the empirical or moral, and is far from satisfactory. Systematic treatments of evidence are generally of three kinds: (1) logical, the most general, and embracing as one of its topics the discussion of the kinds of evidence; (2) historical; (3) legal. It is questionable whether the points of divergence between the legal and the logical treatments of evidence do not outweigh the resemblances. The logical treatment is identical with Methodology at large. See METHOD, and REASONING.

Literature: of historical evidence good treatments are DAUNOU, Cours d'Études historiques; G. CORNEWALL LEWIS, Methods of Observation and Reasoning in Politics. On legal evidence, see FITZJAMES STEPHEN, Digest of the Law of Evidence. (R.A.)

The adjective evident applies to propositions for which the evidence is adequate; but its use in philosophy is rather to describe those truths which are self-evident, or which need no evidence. The transition from one of these meanings to the other appears in the theory of intuitive or innate knowledge, which the mind is said to recognize without evidence, thus making empirical or demonstrative proof unnecessary. See Self-evidence under TESTS OF TRUTH; also CLEAR AND DISTINCT. (J.M.B.)

Evidence (in law): Ger. Evidenz, Beweismittel; Fr. évidence; Ital. prova. The means of proof; facts or means of ascertaining facts, from which other facts may properly be inferred. Any probative matter serving as a legitimate basis of inference as to the existence of a fact. See Thayer's Cases on Evidence, 2.

No matter can constitute a legitimate basis of inference, unless it is relevant to the fact to be inferred, and of a kind which the law permits to be adduced.

In the trial of causes, the best evidence of which the nature and circumstances of the case admit is ordinarily required. If the best evidence cannot be had, secondary evidence may be introduced, that is, evidence of a less direct and convincing character. Direct testimony, sometimes called direct evidence, is that by which a fact in issue can be established without resort to inference, except the usual inference that the testimony of witnesses having personal knowledge of the thing in question is true. It consists of such testimony; which is itself a fact.

Circumstantial evidence is evidence of circumstances from which inferences as to the matter in controversy may legitimately be drawn.

Evidence from witnesses is given orally, or by written depositions over their signature, taken on due notice to the adverse party.

Evidence in chief is the evidence with which the actor or plaintiff opens his case. Evidence in defence is that next introduced by the reus or defendant. Evidence in rebuttal is that which may then be introduced by the actor or plaintiff, to meet the evidence in defence.

Literature: GREENLEAF, on Evidence, i. chap. iii; THAYER, Preliminary Treatise on Evidence at the Common Law (1898). (S.E.B.)

Evidence (internal and external): Ger. Evidenz (innere und äussere); Fr. preuve (interne et externe); Ital. evidenza. The name applied to the main principles by which the higher CRITICISM (q.v.) is guided.

They may be briefly summarized as follows: (1) Internal: (a) a document must consort, as to time, place, and circumstances, with what it purports to be historically; (b) style has many differences, and these may indicate various stages in the career of a single author, or they may imply differences of authorship and of period; (c) differences of opinion and of point of view indicate differences of authorship and of period; (d) the citations made in a document throw important light upon its time and place, and upon its relation to the authorities cited. This is the most difficult of the internal principles to apply in practice. (2) External: (a) definite testimony to a document by other genuine and authoritative writings is of great value for assignment of its period; (b) contrariwise, the silence of writers, who might reasonably be expected to advert to a document, furnishes important evidence of a negative kind. This is much the more difficult of the external principles to apply in practice. It has acquired greater influence and importance in the present century that it had in previous times.

Literature: DU PIN, New Hist. of Ecclesiastical Writers (Eng. trans.), vii f.; H. P. SMITH, in the Presb. Rev. (1882); C. A. BRIGGS, in the Journal of the Society of Biblical Literature and Exegesis (1884). (R.M.W.)


Evil [ME. evel]: Ger. Übel; Fr. mal; Ital. male. That which is contrary to good or well-being.

The classification of evils commonly follows the classification of goods; as into mental, corporeal and external, or, by a more radical division, into natural and moral, i.e. those independent of, and those dependent upon, human volition. It is with the latter that ethics is concerned: the distinction of moral evil from moral good; its ultimate ground and the conditions by which the evil may be overcome and the good attained. Other questions concerning evil have to do with its psychological nature -- whether or not it is identical with pain or tendency to pain; and its ultimate essence -- whether it is something positive, or a mere negation of reality (which is good), or, equally with good, an appearance merely, transcended in the absolute. In the latter reference we have the theological problem of the compatibility of the existence (and origin) of evil with a moral government of the world. See THEODICY, and ORIGIN OF EVIL (also for literature). These questions bring to light the controversy of OPTIMISM and PESSIMISM (q.v.), with which not only scientific ethics, but all reflection upon life, is full. (W.R.S.)

Leibnitz distinguishes three forms of evil: (1) metaphysical (the necessary limitation of the Creator); (2) physical (suffering, lawful penalties, &c.); (3) moral (sin).

Great confusion prevails in the discussion of evil, its origin and nature, from the failure to distinguish moral and natural evils. The theory of pain as a natural or biological fact having its legitimate place and evident utility in the genesis of the organism and in the development of the mind should be kept apart from that of moral evil or sin. The question of mental and moral suffering also should be discussed psychologically and its precise nature determined before it is classed either with physical pain or with moral evil. Dogmatic theology has darkened counsel on the subject by classing all pains together as evils, making them incidents of sin or results of the 'Fall,' and finding it necessary to 'apologize' for their presence in the economy of things. To this is added the further confusion of placing in the same category those external 'evils' which consist in misfortune simply -- the destruction of crops or the spread of the plague -- and are quite apart from the psychologically conditioned 'evils.' Cf. THEODICY, and SIN. (J.M.B.- K.G.)

Evil Eye: Ger. böser Blick; Fr. mauvais oeil. Ital. mal' occhio, fascino, jettatura. The term refers to a widespread belief in the power of certain persons, gifted with the 'evil eye,' to work ill on those upon whom they direct their gaze. It forms one of a large number of practices connected with so-called magic or SORCERY (q.v.). The history of this belief is rather obscure; while its distribution and variations are very wide.

Literature: ELWORTHY, The Evil Eye (1895). See also under MAGIC. (J.J.)

Evocation [Lat. e + vocare, to call out]: Ger. Evocation (suggested); Fr. évocation; Ital. evocazione (suggested). The calling up of a memory by another person, through suggestion, normal or pathological.

The term, in use in French, is recommended for adoption in English (on the suggestion of P. Janet), with the technical use also of the verb to 'evoke.' It is useful in French, and would be also in English, mainly in cases of hypnotic and other alterations of memory in which suggestibility and artificial control of the subject, in some degree, is relatively common. But it is difficult to draw a line between such cases and the normal awakening of memories, by verbal or other suggestions. Cf. Janet, Automatisme psychol. (J.M.B.)

Evolution (in biology) [Lat. evolutus, from evolvere, to unfold]: Ger. Evolution, Entwicklung (development); Fr. évolution; Ital. evoluzione. (1) The continued production of life in accordance with the theory of DESCENT (q.v.). It is opposed to SPECIAL CREATION (q.v.). (J.M.B. E.B.P.)

(2) The theory that individual development is an unfolding of that which already exists preformed in the germ-cells; as opposed to EPIGENESIS. Cf. EVOLUTION (mental).

(1) Setting aside early speculations, based on deduction from assumed general principles, rather than on induction from observed facts and phenomena, a necessary preliminary to organic evolution as a scientific generalization was: (i) the establishment of approximate conclusions as to the age and evolution of the earth, and (ii) a body of evidence as to the succession of organic forms based on a study of fossils. Hence it has been truly said that Lyell was the necessary precursor of Darwin. Such investigation served to establish the fact of progress, but at the same time it emphasized that of apparent discontinuity. There was at first little evidence of fossil species shading continuously one into another; in fact, the very conception of species was opposed to such a view. Darwin, however, by a study of a vast mass of data collected from many sources, and dealing with domesticated animals and plants, species under nature, distribution in space, embryological and paleontological evidences, showed (a) that existing and fossil species are only more or less isolated forms on what are really continuous lines of development: he accounted for apparent discontinuity by the imperfection of the record; (b) that Natural Selection affords good reason that adapted organisms should survive and transmit their adaptations progressively, and gives an intelligible explanation of the facts of geographical distribution, classification, morphology, embryology, and rudimentary organs; (c) that the elimination of intermediate forms between successive relatively stable adapted forms may account for the apparent isolation of these forms along the varied and divergent lines of continuous evolution; (d) that divergence once established would be emphasized, and give rise to independent lines of descent; and (e) that man has produced great results in his domesticated breeds by this very principle of selection working through heredity upon variations. Cf. DOMESTICATION.

In natural selection, of which there had been previous hints, notably in the writings of Herbert Spencer (see Clodd, Pioneers of Evolution from Thales to Huxley), and which was also independently discovered by A. R. Wallace, students of organic nature found a working hypothesis, in accordance with which the theory of evolution could be fruitfully applied. See NATURAL SELECTION, and MALTHUSIANISM. Since the publication of Darwin's Origin of Species, the further development of the CELL THEORY (q.v.) has placed the doctrine of continuity beyond question for existing forms of life, and rendered it in the highest degree probable for all life in the past. The chief problems now under discussion are: (1) the range of natural selection; (2) the nature and limits of hereditary transmission; (3) the theory of variation (the origin, character, amount, and direction or distribution of variations); and (4) whether the theory of evolution as it stands, with all the factors (see FACTORS OF EVOLUTION) now recognized, suffices to account for (i) all forms of adaptation, (ii) specific differences, and (iii) the apparent breaches of continuity between specific forms, present and past. Fuller discussions are given under HEREDITY, and VARIATION.

A recent attempt to treat biological phenomena by mathematical methods has met with great success in the hands of Galton, Pearson, Weldon, and others. Pearson considers quantitative determinations necessary in three great fields before an exact theory of evolution is possible: i.e. (1) variation, (2) selection, and (3) heredity. His own papers have dealt with all of these on the basis of statistical data (Mathematical Contributions to the Theory of Evolution, Proc. Roy. Soc., London, 1894 ff.). For results and methods see (1) VARIATION (different topics), (2) REPRODUCTIVE SELECTION, NATURAL SELECTION, and SELECTION (with the topics mentioned under that head), (3) GALTON'S LAW (of ancestral inheritance), and HEREDITY. These methods apply also to many of the other problems of general biology, such as CORRELATION (q.v.), REGRESSION (q.v.), collateral inheritance, &c.

The distinction between progressive evolution along one line and divergent evolution along different lines has been covered by Romanes by the terms monotypic and polytypic evolution respectively (Darwin and after Darwin, iii).

(2) See PREFORMATION. The general recommendations are made that the term evolution be strictly limited to the first meaning (1), and that Preformation be used for the second (2). Also that the distinction made by Huxley between evolution and DEVELOPMENT (q.v.) be carefully observed. The corresponding German terms are respectively Evolution and Entwicklung; a usage which does away with the ambiguity hitherto arising from using Entwicklung for both evolution and development. The term development will then cover the entire ontogeny of an organism, including the second meaning above (2).

Literature: LYELL, Princ. of Geol.; HERBERT SPENCER, First Princ., and Princ. of Biol.; DARWIN, Origin of Species, Descent of Man, and Life and Letters (by F. DARWIN); WALLACE, Contributions to the Theory of Natural Selection, and Darwinism; HUXLEY, Essays; WEISMANN, Essays, and Germ-Plasm; COPE, Origin of the Fittest, and The Primary Factors of Organic Evolution; OSBORN, From the Greeks to Darwin; LANKESTER, Adv. of Sci.; POULTON, Charles Darwin; HAECKEL, Generelle Morphologie. General expositions are ROMANES, Darwin and after Darwin; CONN, The Method of Evolution (1900). Cf. also the topics mentioned in the article BIOLOGICAL SCIENCES (1). (C.LL.M.- J.M.B.- E.B.P.)

Evolution (mental): Ger. geistigeEvolution (or Entwicklung); Fr. évolution (or développement) mentale; Ital. evoluzione (or sviluppo) mentale. The theory of DESCENT (q.v.), as accounting for the series of minds in the animal forms, including man. It is contrasted with mental development, which is the progress of the individual mind from birth to death.

As in biology, it is well to distinguish the words evolution and development in this way, the one designating the phylogenetic, the other the ontogenetic problem. We are suggesting the same distinction in the foreign equivalents, although in the other languages, as in English, development is often used to cover both.

The hypothesis of mental evolution has very much the place in genetic psychology that the general theory of 'descent' has in biology; in each it is opposed to the well-known 'special creation' theory. And it is becoming more and more evident, as the question of mental evolution is more adequately discussed, that the problem is common to biology and psychology, and must be treated as one broad topic. Biological evolution has to take account of the mental processes at different stages in the life forms, and mental evolution of the physiological organism at each stage. The future evolution theory, in other words, will undoubtedly be a psychophysical theory.

That is is already, in some degree, is seen in the establishment, as factors of evolution, of Darwin's sexual selection, Wallace's recognition markings, and in the working out of a theory of MIMICRY (q.v.) and warning colours. The hypothesis of ORGANIC OR INDIRECT SELECTION (q.v.) also gives, as no other hypothesis has, scope for the effective exercise of the mental faculties in the determination of lines of evolution of both body and mind.

Accordingly, we find that the greater problems of mental evolution are the same, and can generally be put under the same headings as the problems of biological evolution; i.e. the problems of INHERITANCE, or other means of transmission, of acquired mental characters; of the RECAPITULATION of mental evolution in individual development; of mental VARIATIONS and their significance; of SELECTION applied both to minds and to thoughts; of ADAPTATION and ACCOMMODATION (see those terms).

Besides these questions, which the theory of mental descent shares with biology, it has certain problems of its own which biology cannot itself deal with, but which constitute a series of considerations to be carried over from genetic psychology to biology; the questions arising from the facts of social co-operation of all kinds. Under the topic SOCIAL PROGRESS the problem is indicated in more detail; here it may suffice to say that the adaptations and transmissions due to social life, in its widest meaning, in animals and man, are important factors, not only in mental, but also in biological evolution.

The further distinction of mental evolution from social evolution has been attempted, but there is great difference of opinion as to how far it is successful. Mental development in the individual cannot be explained without the recognition both of the social influences which enter into it directly, and also of the strain of individual heredity which indicates the social conditions of the individual's ancestors. Cf. MENTAL DEVELOPMENT, and SOCIAL EVOLUTION AND PROGRESS. Many of the problems of mental evolution centre in the theory of INSTINCT (q.v.).

Literature: DARWIN, Descent of Man; WALLACE, Darwinism; SPENCER, Princ. of Psychol.; SCHNEIDER, Menschlicher Wille, and Thierischer Wille; ROMANES, Mental Evolution in Animals and Man; WUNDT, Hum. and An. Psychol. (Eng. trans.); JAMES, Princ. of Psychol., ii. chap. xxviii; JODL, Lehrb. d. Psychol.; STANLEY, Evolutionary Psychol. of Feeling; LLOYD MORGAN, Habit and Instinct, and Animal Life and Intelligence; GROOS, The Play of Animals (Die Spiele der Thiere, 1896), and The Play of Man (Die Spiele der Menschen, 1899); BALDWIN, Ment. Devel. in the Child and the Race, and Social and Eth. Interpret. See also INSTINCT. (J.M.B., G.F.S.)

Also DE DOMINICIS, La Dottrina dell' Evoluzione (1880); ANGIULLI, La Filosofia e la Scuola (1888); GRASSI-BERTAZZI, I Fenomeni psichici e la Selezione (1898). (E.M.)

Evolution of Religion: see RELIGION (evolution of).

Ex post facto [Lat.]. After the fact. Applied to opinions or arguments constructed to suit, derive, or justify the facts after they are known. It is associated with intellectual pretence. (J.M.B.)

Exact Logic: see LOGIC (exact).

Exact Science: see SCIENCE.

Exaltation [Lat. exaltare, to lift up]: Ger. Exaltation, Aufregungszustand; Fr. exaltation; Ital. esaltazione. Exaltation, as contrasted with depression, refers to a condition of mind in which the mental processes are quickened, and the imagination is active and directed to lofty aspirations. It is also used in a wider sense as synonymous with mental excitement.

Mental exaltation up to a certain degree is normal and physiological, and is particularly natural in childhood and youth, as also among groups or individuals of lively, emotional temperament. It may exceed normal bounds as the result of excessive excitement, of intoxication, or fever, or of distinct brain disease. Considered pathologically, it characterizes a large group of mental disorders (mania and general paralysis chiefly), which take their tone from the excessive excitement and action of brain functions. It refers more specifically in this connection to the delusions of grandeur and vanity, of unusual strength, importance, or wealth, &c., which so frequently accompany mental disease. Such exaltation may affect only a limited range of ideas, or may infuse the entire personality and sequence of thought. Patients believe themselves to be the Lord of lords, Jesus Christ, the king of England, the strongest or wealthiest of men, describe their feats of prowess or skill, their vast possessions, their claims to reverence and greatness. See MEGALOMANIA. Such delusions of exaltation may be accompanied by actual hallucinations, which fortify the subject in his beliefs. Insane exaltation of this type may ensue as a primary mental disorder, the exaggeration of a temperamental disposition; it more usually appears as a symptom or sequel of mania (occasionally of melancholia) or of other specific forms of insanity (insanity of masturbation, epileptic insanity, general paralysis).

Literature: CLOUSTON, Ment. Diseases, particularly lect. iv; general textbooks of mental disease (KRAFFT-EBING, MENDEL, MORSELLI), and monographs on mania. (J.J.)

Example: see REASONING.

Excellence [Lat. excellens, high]: Ger. Vortrefflichkeit; Fr. excellence; Ital. eccellenza. A high degree of WORTH (q.v.) or value, of whatever kind; not a technical term.

The excellences of character which are shown in a man's habitual conduct are called virtues. Virtue is thus excellence which is human, voluntary, and established as a habit of character. The Greek term areth meant excellence, especially of manly quality. In the writings of Plato, and still more definitely of Aristotle, it gradually acquired the special and technical signification of VIRTUE (q.v.). The term excellence has preserved the wider and less technical signification. (W.R.S.)

Excess or Overproduction: Ger. Ueberschuss; Fr. excès; Ital. sopraproduzione. The principle that results analogous to those of conscious choice or determinate variation are secured by the excessive or over-production of variations, giving materials for the survival of the fittest. It is part of the conception of NATURAL SELECTION (q.v.).

Special applications of it have been made in GERMINAL SELECTION (q.v.) and in the theory of the acquisition of voluntary movement by the production of excess movements through a diffused nervous discharge (Spencer), imitatative effort, &c. According to this latter theory the individual proceeds by trial and error, and gradually secures the adaptive combinations. Spencer (Princ. of Psychol.) and Bain (Emotion and Will, 4th ed.) gave currency to this view of the acquisition of movements; it has been called by the present writer (Ment. Devel. in the Child and the Race, 2nd ed., 1896) 'Functional Selection.' Cf. also Lloyd Morgan, Habit and Instinct. (J.M.B., C.LL.M.)

Exchange [Lat. ex + cambiare, to change]: Ger. Wechsel; Fr. échange; Ital. scambio. (1) The transfer of rights to wealth from one individual to another. (2) In commercial, as distinct from theoretical usage, the means employed for the transfer of rights and credits from one locality to another, especially (foreign exchange) when those localities are situated in different countries.

Exchange, in its first or broader sense, was first made one of the main divisions of economic science by James Mill, and has since ranked in many standard textbooks as one of four co-ordinate 'departments' of political economy -- production, distribution, and consumption being the other three. (A.T.H.)

Excitability [Lat. excitare, to call forth, to wake up]: Ger. Reizbarkeit; Fr. excitabilité; Ital. irritabilità. Power of responding with an appropriate reaction to normal stimulus. See NERVE STIMULATION, and LIVING MATTER. (C.F.H.)

Excitation: Ger. Erregung; Fr. excitation; Ital. eccitazione. The vital change set up by the action of a STIMULUS (q.v.).

Literature: see the psychological and physiological textbooks, especially KÜLPE, Outlines of Psychol., 81; WALLER, Human Physiol. (1891), 291. (E.B.T.)

Excitement: Ger. Aufregung; Fr. excitation; Ital. eccitazione, eccitamento. Heightened condition of consciousness, especially in its conative and affective aspects.

The term 'excitement' is the psychological counterpart of the physiological term 'excitation.' Both words presuppose something which is excited or 'called into action.' On the physiological side this is nervous tissue, and excitation is a process taking place in nervous tissue. On the psychological side, what is excited is regarded as a condition of conscious process -- a psychical disposition or predisposition. According to the current hypothesis of psychophysical parallelism, psychical dispositions, &c., are throughout correlated with physiological; permanent possibilities of conscious process involve permanent possibilities of nervous process. It is open to the psychologist to consider the physiological side of the total psycho-physiological occurrence so far as he finds it useful to do so.

Under this definition excitement may be looked upon as variation in the quantity, considered apart from the hedonic tone, of emotion. Very high excitement may be supposed to be present with relatively neutral or mixed pleasure-pain tone.

Literature: BAIN, Emotion and Will; STOUT, Manual of Psychol.; BALDWIN, Feeling and Will, chap. x. § 1. (G.F.S.- J.M.B.)

Excluded Middle (principle of): Ger. Grundsatz des augeschlossenen Dritten (oder Mitte); Fr. principe du tiers (milieu ou moyen) exclus; Ital. principio del terzo escluso. The principle or axiom of excluded middle (or third) formulates one aspect of the simple and universal condition of knowledge -- that every judgment must be either true or false.

Between the assertions, then, which express the truth and the falsity of any significant judgment (for the meaningless has no right to recognition as judgment), there is no medium; one or other must be true. Obviously it is necessary, in order to avoid confusion regarding the scope and nature of this principle, to exercise the greatest care to secure that the assertions do no more than express the truth or falsity of some relation represented in thought, a condition not easily satisfied if there be any ambiguity in the subject of the assertions considered. Cf. LAWS OF THOUGHT.

Literature: for history, see UEBERWEG, Logik, § 78; HAMILTON, Lects. on Logic, lect. v; DELBOEUF, Essai de Logique scientifique, 165 ff.; SIGWART, Logik, § 25. (R.A.)

Exclusi tertii principium (in logic) [Lat.]. The principle of EXCLUDED MIDDLE (q.v.). (J.M.B.)

Exclusion: see LAWS OF THOUGHT.

Exclusion (method of): Ger. Methode der Exclusion; Fr. méthode d'exclusion; Ital. metodo di esclusione. That portion of Bacon's general view of induction which consists in eliminating by comparison of cases, particularly of negative cases, all that is non-essential -- the residue, if the exclusions be made adequately, being necessarily the real cause involved. 'Whenever Bacon speaks of ordinary induction and of his own method he always remarks that the former proceeds per enumerationem simplicem, that is, by a mere enumeration of particular cases, while the latter makes use of exclusions and rejections' (Ellis, in Bacon's Works, i. 34).

On the conditions of the method, its limitations and character, as conceived by Bacon, cf. Ellis, loc. cit., 35-9, and Fowler's ed. of the Nov. Org., Introd., § 9. The general nature of inductive processes as methods of exclusion or elimination of the non-essential is well stated in Bain, Induc. Logic, chap. v. (R.A.)

Excommunication [Lat. ex + communicatio, partnership]: Ger. Excommunikation; Fr. excommunication; Ital. scomunica. This word means strictly the ban of the Church, although it is sometimes applied, figuratively, to expulsion from other associations.

After the Council of Nicaea, and during the centuries in which the Church was supreme, excommunication took two forms. Excommunicatio minor deprived the condemned of the sacraments; excommunicatio major deprived him of all religious consolations -- even of burial in consecrated ground -- and barred him from all intercourse with Christian people. Necessarily, the state has to be called upon to enforce the second part of this ferocious penalty, and by the beginning of the 13th century we find it co-operating with the ecclesiastical authority. After the Reformation the greater excommunication was abolished, in Protestant realms, as a civil punishment, but the lesser was often enforced, as in Scotland, as a necessary part of ecclesiastical discipline. In these circumstances, the position of the Roman Catholic Church towards the greater excommunication has become largely theoretical.

Literature: KOBER, Der Kirchenbann; GOESCHEN, Doctrina de discp. ecc. ex ordinationibus; RÜETSCHI, Bann bei den Hebräern, in Herzog's Real-Encyc.; any history of mediaeval society and times. (R.M.W.)

Executive (in law) [Fr. exécutif]: Ger. Executiv, Staatsgewalt (executive power); Fr. (see above); Ital. esecutivo (potere). Pertaining to the execution of laws; or the supreme magistrate or magistracy charged with the execution of the laws. Executive requisition: a demand by the executive of one state upon the executive of another, for the surrender of a fugitive from justice.

It was the doctrine of Montesquieu in his Esprit des Lois, and the belief of many American statesman in the 18th century, that the executive power could be separated by clear lines from the legislative and judicial. Experience has shown the contrary. A large field of governmental action, known as administrative, while lying mainly in the control of the legislature, may be committed by it, in great part, to the executive magistracy (Story, on the Constitution of the United States, ii. 524; Pomeroy's Constitutional Law, § 173).

Literature: WOOLSEY, on Polit. Sci., ii. chap. ix. (S.E.B.)

Exegesis [Gr. ek + hgeomai, to lead]: Ger. Exegese; Fr. exégèse; Ital. esegesi. The object of one of the four main departments of theology -- exegetical theology (the others being historical, systematic, and practical theology).

The object is the interpretation of the, and any, authoritative sacred books. In the scheme of Christian theology it is usually divided into two parts -- Old Testament and New Testament exegesis. Historically viewed, it may be divided into periods, in each of which contrasted methods and presuppositions prevailed. Thus we have rabbinical exegesis, patristic exegesis, mediaeval exegesis, modern exegesis. The apparatus employed in the last is vastly more extended and much more scientifically applied than in the others.

Literature: this is enormous, and is fully given in Herzog's Real-Encyc., arts. Exegese, Hermeneutik; REUSS, Hist. of the New Testament (Eng. trans.); WOGUE, Hist. de la Bible et de l'Exégèse jusqu'à nos Jours. (R.M.W.)

Exercise [Lat. ex + arcere, to enclose, through Fr.]: Ger. (1) Einüben (-ung), (2) Ausüben (-ung); Fr. exercise; Ital. esercizio. (1) Learning or training through doing or practice; also the function or task which is the means of it. See HABITUATION, and cf. PREPARATION.

(2) The performance of a function or task in which the performer is more or less competent; also the function or task in question.

Exercise is in one case practice into a function -- an ACCOMMODATION (q.v.) process; in the other it is the practice of a function -- an expressive or keeping-up process, a giving scope to what has already been acquired. See TERMINOLOGY (German), 'Ubung.' The second meaning is recommended. (J.M.B.)

Exhaustion: see LAWS OF THOUGHT.

Existence [Lat. existens, existent]: see REALITY AND EXISTENCE, and cf. BEING.

Existence (struggle for): Ger. Kampf ums Dasein; Fr. lutte pour la vie, concurrence vitale; Ital. lotta per l'esistenza (or per la vita). The attempt to remain alive, or technically to survive, on the part of organisms. As a necessary factor in Darwinism, the conception involves the further restrictions: (1) that the organism which survives is already or still capable of propagating in the manner normal to its species; and (2) that it finds opportunity to do so: failing either of these conditions, the case would not be one of successful struggle for existence, from the point of view of evolution.

Three clearly distinguishable forms of struggle for existence may be distinguished.

(1) The competition for food, &c., that arises among organic beings through overproduction.

(2) Competition in any form of active contest in which individuals are pitted against one another.

(3) Survival due to greater fitness for life in a given environment, whether combined with direct competition with other organisms or not.

The second case (2) is that in which animals (a) fight with, or (b) prey upon, one another, only the former of these having any analogy to the form of competition due to a limited supply of food, &c., and then only in the case in which the strife results from the circumstances of getting a living -- not in the case of mere combativeness, in which the stronger animal kills from aggressiveness. In case (b) one animal feeds upon members of another group as his natural prey -- as the eating of insects by birds, leading to special adaptations for concealment, warning, &c., in the species preyed upon. This has nothing to do with overproduction to compensate for the constant drain upon it (a very different thing).

A case of (2 a), important for its effects upon the next generation, is that of the struggle of males for the female, occurring irrespective of the number of available females. Cf. SEXUAL SELECTION.

The third case of 'struggle' (3) is that in which individuals struggle against fate -- the inorganic environment -- not against one another. This is really a 'struggle to accommodate,' to reach a state of adjustment or balance under which continued living is possible; as the other forms are respectively 'struggle to eat' (in a large sense), and 'struggle to win,' so this is 'struggle to accommodate.' The distinction between cases (2) and (3) disappears in instances in which the animal accommodates actively to meet his enemies, which then become part of his environment in the sense of case (3).

The relation of large productiveness to this form (3) of the struggle would seem to be but indirect. It would not matter how many individuals perished provided some lived; and any amount of overproduction would not help matters if none of the individuals could cope with the environment. Yet the theory of indeterminate, or indefinite, variation makes the chances -- under the law of probability -- of the occurrence of any required variation a definite quantity, and these chances are of course increased, i.e. for so many more variations another chance of one that is fit -- with increased production. No better case in point could be cited than Dalliger's experiments on the effects of changes of temperature on infusoria.

In recent evolution theory the doctrine of natural selection has come to rest more and more on the second and third sorts of struggle (2 and 3), and less on the Malthusian conception (1). Experimental studies which support the selection view (e.g. Weldon on Crabs, Poulton on Chrysalides) show the eliminative effect of the environment, and the preying of some animals upon others, rather than direct competition inter se, among individuals of the same species, for food or other necessities of life. It is these forms of the struggle, too, that we find nature especially providing to meet through concealing and warning colours, mimicry, &c., in the one case, and high plasticity and intelligent action in the other.

The result common to all the sorts of struggle for existence, however, is the survival of an adequate number of the fittest individuals, and this justifies the use of the term in the theory of evolution to cover the wide variety of instances. Cf. NATURAL SELECTION, INTRASELECTION, GERMINAL SELECTION, and GROUP SELECTION. (J.M.B., E.B.P.)

Darwin on reading Malthus, On Population, conceived the idea that over-population would be a universal fact in organic nature, were there no process by which the numbers were constantly reduced. He was thus led to lay stress on the struggle for existence, and the elimination of those individuals which were unsuccessful. Combining this conception of elimination in the struggle with that of variation, he reached the hypothesis of natural selection. A similar relation to Malthus is true of Wallace (see Poulton, Charles Darwin). In this case the competition arises from common wants and an inadequate supply for all, the competition being either direct rivalry of one animal with another, or mere lack of something necessary to some.

Literature: MALTHUS, On Population (1798); CHARLES DARWIN, Origin of Species (1859); F. DARWIN, Life and Letters of Charles Darwin (1887). (C.LL.M.- J.M.B., E.B.P.)

Existence of God: see THEISM.

Existential Judgment: Ger. Existentialsatz; Fr. jugement d'existence; Ital. giudizio di esistenza. A judgment in which the existence of the subject is explicitly predicated. See JUDGMENT, and PROPOSITION. (G.F.S.)

Exner, Franz. (1802-53.) Born and educated in philosophy and jurisprudence at Vienna. In 1827 he taught philosophy in the same place, and in 1831 became professor of philosophy at Prague. In 1848 he was called to Vienna to enter the ministry, and died as ministerial commissary to Padua.

Exogamy [Gr. exw, outside, + gamoV, marriage]: Ger. Exogamie; Fr. exogamie; Ital. esogamia. Marrying out: a term (proposed by McLennan) for the custom which requires a man to take a wife from some other clan or tribe than his own.

The custom in various forms is most widely distributed, both amongst savages and in all stages of civilization. Its origin has formed the subject of much discussion, from which no consensus of opinion has as yet resulted. The institution was, in many instances, a sacred one, its violation being punishable with death; and it was evidently connected with the recognized degrees of relationship, particularly whether tribal, paternal, or maternal, which marriage brought about. Its discussion thus involves the general question of the history of human marriage and kinship, and the evolution of the family, clan, and tribe. Apart from minor factors and supplementary causes of exogamy in special cases, the two dominant factors assigned for its dissemination are: (1) the noxious and weakening effects which result from too close inbreeding of families, which in turn leads to a psychical lack of sexual attractiveness among those who have grown up closely together, and who are usually of near kin (the view of Westermarck, &c.); and (2) the scarcity of women in primitive communities owing to the practice of female infanticide, and the consequent tendency to marriage by capture from other tribes (the view of McLennan). The opposite of exogamy is endogamy, or the prohibition of marriage outside of the tribe. The relation in evolution of one to the other is not very clearly established.

Literature: MCLENNAN, Stud. in Amer. Hist. (1st and 2nd series, new ed., 1886 and 1896); WESTERMARCK, The Hist. of Human Marriage (1891); LETOURNEAU, The Evolution of Marriage (1895); STARCKE, The Primitive Family (1889). (J.J.)

Exorcism [Gr. exorkismoV, administration of an oath]: Ger. Beschwörung, Exorcismus; Fr. exorcisme; Ital. esorcismo. The act of expelling evil spirits from persons or places by the pronouncing of formulas, or the observance of prescribed rites.

The process, under various forms, is almost as widespread as mankind, and derives its origin from the conception that disease and ill-fortune are produced by some evil spirit or demon. The cure of the disease or the removal of the misfortune can be accomplished only by the exorcism, or at times by appeasing the possessing spirit through offerings. Among primitive peoples the ceremonies of exorcism are often extremely crude, such as the frightening of the spirit by beating of drums and the cries of bystanders; while in more advanced civilizations which inherit traditional religious systems, the formulas and rites assume a very elaborate and specialized form. It was naturally the priest's function to deal with spirits, and it equally became his function to act as physician and effect cures, by driving out the spirits. Almost every nation of history has recorded some formulas and magical proceedings which custom and authority brought into use for the exorcism of the various ills that flesh is heir to; while survivals of these, frequently in a broken-down and weakened form, are current to the present day. It received special recognition in Christian rituals, especially that of Baptism. Similar processes were applied to haunted houses, or ill-fated places. Cf. ANIMISM, DEMONOLOGY, and MAGIC, and consult the references there given. (J.J.)

Exoteric: see ESOTERIC.

Expectation [Lat. ex + spectare, to look]: Ger. Erwartung; Fr. attente, expectation; Ital. aspettazione, attesa. Belief that future experience will be of a definite sort, based upon past experience. 'Any man knows that he will die, and may make a variety of arrangements in anticipation of death, but he cannot with propriety be said to be expecting it unless he has actually present to his mind a series of ideas ending in that of death, such series being due to previous associations, and unless, further, this series owes its representation at this moment to the actual recurrence of some experience to which that series succeeded before' (Ward, Encyc. Brit., art. Psychology, 63).

Expectation arises from the so-called 'memory-coefficient' of reality (see BELIEF); that is, it is aroused by those marks of memory-images which serve to bring the assurance that they represent a former real series of experiences capable of being tested either by voluntary activity, as in going to the corner which I am expecting to find, or by submission to the series of events which lead up to the one expected and condition my activity, as in keeping my eyes open at the panorama until the expected portrait of Washington comes on. Expectation is the word for that attitude towards reality in general which concerns itself with what Mill expressed, in the case of the external world, as 'the permanent possibility of sensation,' and which has been more adequately formulated as voluntary control of a memory series, in such a way as to bring back the original evidence of reality or truth under conditions of limitation of activity. Expectation has been made use of by Hume in his theory of causation, and by Mill in his discussion of the uniformity of nature, and its degrees -- or rather how much right we have to expect -- are given mathematical expression in the theory of PROBABILITY (q.v.). (J.M.B., G.F.S.)

Expediency [Lat. expedire, to hasten]: Ger. Nützlichkeit; Fr. utilité; Ital. utilità. The quality of being advantageous for, or adapted to promote, the interest in view. See UTILITY.

The expedient in this sense is often contrasted with the right -- the latter being determined by an absolute rule or law, whereas the former seeks its interest independently of the law. But when the interest or end of conduct is widened so as to include not merely individual but general happiness, and when this is regarded (as by the utilitarians) as the rule of right, the contrast disappears. Thus Paley says: '"Whatever is expedient is right." But then it must be expedient on the whole, at the long run, in all its effects collateral and remote, as well as in those which are immediate and direct.'

Literature: PALEY, Mor. and Polit. Philos., Bk. II. chaps. vi-viii; J. S. MILL, Utilitarianism, chap. ii. (W.R.S.)

Expense [Lat. expensum, money spent]: Ger. Selbstkosten, Ausgaben; Fr. dépense, prix de revient; Ital. spesa. Cost measured in money.

In the production of any article or service there are usually two kinds of expense: the special expense connected with the production of that particular article, which will be saved if the article in question is not made; and an indeterminate share in the general expenses connected with the maintenance of the factory, or other industrial enterprise -- expenses which go on with little or no diminution, even if the particular article in question ceases to be made. Expenses of the former class are called direct, distributed, prime, or operating expense; those of the latter are called indirect, undistributed, supplementary expenses, or fixed charges. (A.T.H.)

Experience [Lat. experientia, from experior, to try]: Ger. Erfahrung; Fr. expérience; Ital. esperienza. (1) Psychological: consciousness considered as a process taking place in time. We can speak of an experience, meaning a specific phase or mode of conscious change, or of experience as a whole, meaning the events of the mental life in general. (G.F.S.- J.M.B.)

The word is used so vaguely and ambiguously by writers on philosophy that definition is difficult. We find for instance such writers as Royce and Bradley speaking of an 'absolute experience' which is not subject to time conditions. This usage seems to deprive the term of all distinctive meaning. An experience in the historical and ordinary application of the term is a phase of conscious life which some individual 'passes through' or 'undergoes.' This does not imply mere passivity on the part of the individual. On the contrary he may, and does, anticipate or search for many of his own experiences. So far as this is the case experience includes 'experiment' in the widest sense, and involves a process of trial and error. (G.F.S.)

(2) Psychic or mental: the entire process of phenomena, of present data considered in their raw immediacy, before reflective thought has analyzed them into subjective and objective aspects or ingredients. It is the summum genus of which everything must have been a part before we can speak of it at all.

In this neutrality of signification it is exactly correlative to the word PHENOMENON (q.v.), meaning (4). If philosophy insists on keeping this term indeterminate, she can refer to her subject-matter without committing herself as to certain questions in dispute. But if experiences be used with either an objective or a subjective shade of meaning, then question-begging occurs, and discussion grows impossible. (W.J.)

The distinction between the meanings (1) and (2) is that between the two points of view of PSYCHIC (or MENTAL) AND PSYCHOLOGICAL (q.v.), as made in many places in this work. The neutrality and immediacy of meaning (1) is psychic, i.e. neutrality with reference to the subject which may be having the experience. When philosophy uses this meaning it is by abstraction from the content of the experience as thought in which the experience defined as neutrality has its place. That is, this neutrality can be postulated only of phenomena having some sort of psychic phase to which the phenomena are immediate. To make the term synonymous with raw unexperienced process, from the objective point of view, would be to go over to another extreme of interpretation. (J.M.B.- G.F.S.)

Locke's polemic against innate ideas supplies an excellent illustration of the use of the term. His position on this point is in reality a special form of protest against blind submission to authority, as contrasted with the method of finding out for ourselves by direct contact with reality. For Locke an 'innate idea' implied a belief thrust upon the mind from a foreign source, instead of arising in the normal course of the development of consciousness in relation to its objects. Since the starting-point of this development is in sense-experience, Locke insists that we cannot have ideas prior to or independent of sensations.

A distinction is frequently drawn between 'internal' and 'external' experience. But there is great confusion in the use of these terms. A thing may, in the same sense of the word, be in one place and therefore not in, i.e. out of, another; but we express no intelligible relation if we speak of two things as being, one in a given room and the other in last week. Yet evident as it seems that the correlatives in and not-in must both apply to the same category, whether space or time, presentation (or non-presentation) to a given subject, and so forth, we still find psychologists more or less consciously confused between 'internal,' meaning presented in the psychological sense, and 'external,' meaning not 'not--presented,' but corporeal or oftener extra-corporeal (Ward). If we insist on logical stringency, it would seem that no distinction between inner and outer experience is tenable. Suppose that 'inner' is taken to mean inside, and 'outer' outside the body. When we speak of experience as inside the body, we can only mean 'arising in connection with certain material processes which occur within the body'; but in this sense all experience is equally internal.

Suppose, next, that 'outer' is taken to mean 'having a spatial character and relation.' and 'inner' to mean non-spatial. On this view, again, all experience is equally internal. Feeling, thinking, and willing are not spatial processes; they have no shape or position: it is true that spatial relations are presented to consciousness; but the presentation of them is not an event in space. Suppose, in the third place, that 'inner' is taken to mean whatever forms a part or phase in the stream of processes constituting the existence of an individual consciousness, and 'outer' whatever is distinct in existence from this stream of processes. Here it is evident that the definition of 'internal' experience coincides with the definition of experience in general.

It thus appears that the attempt to distinguish two kinds of experience, one of which is 'external' and the other 'internal,' breaks down hopelessly. None the less the use of such phraseology is so persistent and widespread that we must assume it to be founded on some real distinction. The actual state of the case appears to be as follows. All experience is internal, in the sense of being inside or constituting part of the existence of an individual consciousness. But this statement implies nothing as regards the nature of the object to which experience refers -- the object of which it is an experience. My thinking is always a conscious process; but I am not always thinking about conscious process. When I think of the moon, I mean something distinct in existence from my own stream of consciousness or any part of it; the object, as I at the moment understand it, is by its intrinsic nature something which would have existed if I had never been born. On the other hand, I may think of an emotion of disappointment or anger which I remember feeling yesterday, or am feeling now, or am likely to feel to-morrow. Here, not only is the process of thinking an experience of mine, but the object thought of is also an experience of mine. Now the phrase 'internal experience' seems to refer especially to cases in which an experience has other experiences of the same subject for its object; or to cases, if such there be, in which an experience is immediately aware of itself as such. External experiences, on the other hand, are experiences which have for their object whatever is taken to be distinct in existence from the stream of individual consciousness or any part of it.

The two sorts of experience are, however, largely correlative. We cannot reflect on our own states without taking account of their objects in some measure. It is a disputed question, how far it is possible to know other things without at the same time having some apprehension of the self and its processes. But it seems that ordinarily in the developed human consciousness some such self-awareness is present, though it may be relatively dim and vague. On the various interpretations of experience see IDEALISM, EPISTEMOLOGY, and NATIVISM AND EMPIRICISM. For literature, see BIBLIOG. B. i, d. (G.F.S.)

Experiment [Lat. experimentum, a trial]: Ger. Versuch, Experiment; Fr. expérience; Ital. experimento. The alteration of phenomena or of the methods of observing phenomena, in order to obtain knowledge regarding them.

Wundt defines an experiment as 'observation connected with an intentional interference on the part of the observer, in the rise and course of the phenomena observed,' which definition follows Mill and other writers. Common usage, however, would call an observation made under artificial conditions, as with instruments, an experiment. Mill remarked that experiments have a very limited range in mental philosophy, whereas Wundt holds that observation having to do with objects, and experiment with processes, the experimental method alone is valid in individual psychology, and that there is no fundamental psychical process to which it cannot be applied. (J.McK.C.)

Experiment in the general sense then is not opposed to observation, but is a special type of it, and where applicable at all, adds immensely to the information which might be yielded by observation, while at the same time enabling much to be known that would never fall within the compass of observation. Experiment is the most potent instrument for effecting that elimination of the accidental which is the necessary preliminary to the establishment of a law of fact, and has an equally important function in the indispensable work of verifying or testing any generalization by comparing it with fact. Like observation, it is a directed and controlled process, and is therefore always in the service of a varying mass of already acquired knowledge. The general principle regulating inference from experiment is formulated in the canon of the method of DIFFERENCE (q.v.). For Crucial Experiments see EXPERIMENTUM CRUCIS. (R.A.)

Experimental Science: see SCIENCE.

Experimentation or Experimenting (as a mental process): Ger. Experimentiren; Fr. expérimentation; Ital. (lo) sperimentare. The process of 'trial and error,' or 'try-try-again,' considered as a natural method of securing results for which no direct way of attainment is known.

Animals and children proceed by experimenting in many instances. In cases of motor accommodation it is aided by the process of EXCESS (q.v.) or overproduction.

Literature: GROOS, Die Spiele d. Thiere (Eng. trans.), also Die Spiele d. Menschen (Eng. trans.); LLOYD MORGAN, Habit and Instinct. (J.M.B.)

Experimentum crucis [Lat.]. An EXPERIMENT (q.v.) so arranged that its results will be final or crucial in solving a problem: as the introduction of a flame into a jar to determine whether one of a group of inflammable gases is present or not. (J.M.B.)

Expiation: see ATONEMENT.

Explanation [Lat. ex + planus, smooth]: Ger. Erklärung; Fr. explication; Ital. esplicazione. Any relative clearing up of a perception or notion in terms of judgments or notions already assented to.

There has been much discussion as to what constitutes real or ultimate explanation, the matter of dispute being the final terms to which the thing explained may be reduced -- to axioms, to self-evident or a priori truths, to invariable sequence, to descriptive or analytical judgments. Explanation in positive science means the reduction of a phenomenon to the terms of a general principle, whatever that principle be; it may be reached by empirical and experimental methods, and is then called (following Platner) empirical explanation. The deductive derivation of a fact or notion from universal truths may be called in contrast logical explanation, which becomes metaphysical when the universal is one to which metaphysical validity is attributed.

Explanation is often made synonymous with DEFINITION (q.v.), but definition is a more restricted term. Definition follows upon explanation, and consists in the statement of the explanation in its lowest terms, and in certain forms which satisfy logical tests. Moreover, the logical demand of definition may be filled from the point of view of formal precision within the limits of knowledge, while the psychological demand for explanation may be unsatisfied. Further knowledge in this case may furnish an explanation which in turn may result in a new definition. Cf. REASONING.

Literature: the general works on logic, especially MILL, SIGWART, ERDMANN, BOSANQUET, and WUNDT; VENN, Empirical Logic; JEVONS, Princ. of Sci; PEARSON, Grammar of Sci. (2nd ed.). (J.M.B.)


Explicite: see IMPLICITE.

Exponible: see PARVA LOGICALIA.


Expression (aesthetic) [Lat. exprimere, to press out]: Ger. Ausdruck; Fr. expression; Ital. espressione. (1) The act of expressing or conveying meaning. Often with the connotation of clear, forceful, penetrating, and emotionally appropriate manner. (2) The meaning itself of an object or work or art, as distinct from the act or manner of conveying it. (3) The manner in which any part or the whole of an object or work of art imparts its peculiar significance, and in the latter case more specifically the mode in which the artist reveals ideas and emotions, whether in interpretation of nature and mankind, or as embodying his own immediate subjective experience as such. For the relation of expression to beauty, see BEAUTY (II and III).

Expression as a constituent element of aesthetic value appears to have been explicitly recognized by Socrates. It is somewhat incidentally treated by Aristotle, who mentions it, in the sense in which it indicates expression of character, as a feature in good painting, and a matter of distinct importance in tragedy. He also compares to their disadvantage in this respect the formative arts with music. Plotinus recognizes it indirectly, but it does not become a principle of fundamental significance until its development by Winckelmann. The subsequent history of art shows in many directions reflections of the principle under the influence of the larger spirit of Romanticism. The emphasis upon the expression of individuality and the characteristic, together with the tendency to break from slavish adherence to classicism and the accepted models of art, is illustrated in poetry by Goethe, Schiller, and Byron; in the treatment of the novel by Victor Hugo; in painting by the cultivation of landscape, as exemplified by Corot and Turner, and in the development of genre by such men as Millet and Bréton. Wagner may fairly represent this trend as affecting music. In sculpture and architecture the influence of the principle is no less truly felt, but it is mingled with other influences. Schwanthaler and Lassus may, however, serve as illustrations. Cf. CHARACTERISTIC, and ART THEORIES.

Literature: BOSANQUET, Hist. of Aesthetic (1892); VAN DYKE, Princ. of Art (1887); VÉRON, Aesthetics (1879); TAINE, Lects. on Art (1896, 2nd ed.); SANTAYANA, The Sense of Beauty (1896); SULLY PRUDHOMME, L'Expression dans les Beaux-Arts (1898); Gurney, Power of Sound (1880); v. HANSEGGER, Die Musik als Ausdruck (2nd ed., 1887). (J.R.A.)

Expression (facial): see PHYSIOGNOMY, and EMOTIONAL EXPRESSION.

Extension [Lat. ex + tendere, to stretch]: Ger. Ausdehnung; Fr. extension; Ital. estensione. A continuous, coexistent, manifold of positions, in which the distance and direction of the constituent parts are not qualitatively determined. Cf. SPACE.

There are many kinds of serial arrangement. Extension is distinguished from time series, because its constituent parts are coexistent, not successive. It is distinguished from qualitative and intensive series, such as the scale of pitch, because the order of its parts is not dependent on the intrinsic nature of each part. The reason why one tone is placed between two other tones in the scale of pitch, is that comparison shows it to be higher than one of them, and lower than the other. The relative position of the parts of extension is not fixed in this way by qualitative comparison.

Psychological theories of the perception of extension have been roughly divided into two classes: (1) the nativist; (2) the genetic. The purely nativist theory maintains that all perception of extension is due to original endowment, so that it can no more be accounted for by psychological conditions than the sensations of colour or sound. The purely empirical form of the genetic theory wholly denies both that the perception itself is a matter of original endowment, or that it contains any constituent factor exclusively belonging to it which is due to original endowment, and so incapable of psychological derivation or explanation. As an example of the purely empirical view, we may refer to the attempt of Bain, J. S. Mill, and others to reduce the whole perception of extension to series of motor sensations combined in certain ways, and occurring in a time series. Unreflective common sense resorts to the form of nativism which makes space a matter of psychologically immediate perception. Older writers, such as Hobbes and Locke, never seem to have thought of doubting it. Berkeley is a nativist as regards the tactual perception of extension in all its forms, and also as regards the visual perception of the second dimension. But he was the first to call in question the possibility of directly perceiving the third dimension by sight. He made the perception of distance from the eye a result of the association of visual with tactual experiences. In modern times it is difficult to find any competent authority for a purely nativist position such as would support the Kantian view of SPACE (q.v.) as an a priori form. Nativist writers, while affirming an original perception of extension both by sight and touch, usually regard this perception as at the outset vague and rudimentary; its further development is regarded by them as due to experience, and capable of psychological explanation (Stumpf, Hering, &c.). Others, who have been called 'nativists of process' (Lotze, Wundt), hold that extension is reached by a functional synthesis of unextensive data (intensive and qualitative) which are called LOCAL SIGNS (q.v.). These writers consider their theory genetic, though not empirical. A third view current at the present time cannot properly be called either nativist or empirical. It is empirical as regards the form of extension; but it is nativist as regards the matter which is arranged in this form, although on this distinction its two main advocates, Ward and James, do not seem to be in complete agreement. It regards the serial order of positions, distances, &c., as the result of mental processes which are traceable by the psychologist. But it maintains at the same time that the matter which assumes this form is, in part at least, of a peculiar kind distinctively belonging to the perception of extension, and due to an original and irreducible kind of sense-experience. This ultimate sense-experience is called extensity (Ward), or extensiveness (James). See EXTENSITY. Discussion is now very largely between the genetic nativism (of process) and this sensational or 'original quality' view.

Locke uses the term 'expansion' instead of extension. It is obvious that according to the definition sounds, (smells, &c.), are not extended. There are no audible positions co-existent with each other, and separated and connected by audible distances. It would seem to be a legitimate problem to ask why there are not, i.e. what local signs they lack, or why their extensity (if they have it) does not develop into extension.

Literature: HERBART, Psychol. als Wiss., §§ 109-15; VOLKMANN, Lehrb. d. Psychol., §§ 90-9; LOTZE, Metaphysik, §§ 543-73; Medicin. Psychol., §§ 325-435; Grundzüge d. Psychol. (4th ed.), §§ 31-43; BAIN, Senses and Intellect (4th ed.), 196-204; T. K. ABBOT, Sight and Touch; STUMPF, Die Raumvorstellungen; WUNDT, Physiol. Psychol. (3rd ed.), ii. 28 f. and 189 ff.; Logik, ii. 457-60; LIPPS, Grundthatsachen, 475-587; WARD, Encyc. Brit. (9th ed.), art. Psychology; JAMES, Princ. of Psychol., ii. 132-282; STOUT, Manual of Psychol., 330 ff.; VICTOR HENRI, Die Raumwahrnehmungen des Tastsinnes, §§ 159-214; the Psychologies of LADD and BALDWIN contain many literary references. (G.F.S.- J.M.B.)

Extension (in physics). That property of matter in virtue of which it seems to occupy space. It is intimately associated with IMPENETRABILITY(q.v.).

In mathematics: the property of occupying space in one or more dimensions. (S.N.)

Extension (logical): Ger. Umfang; Fr. extension; Ital. estensione. The extension or extent of a general notion is the whole range of concrete objects, lower classes, cases or instances in which are found the distinctive characters making up the COMPREHENSION (q.v.) of the said notion. See also QUANTITY (in logic).

The distinction between the two aspects of all generalizing thought, the reference to the concrete instances on the one hand, and the relatively abstract marks or meaning on the other, is so fundamental that it could not but make itself felt in the earliest scientific analysis of thought, in the Aristotelian logic, though it did not then receive any special denomination. The same lack of definite naming is traceable in the whole scholastic logic. It is only in the 15th century that some indications of the distinction as having logical significance began to appear, and in modern logic recognition of its value dates from the Port Royal Logic, 1662. Leibnitz, Wolff, and Kant, with their followers, as they tried to make the notion the unit of logical thought, naturally assign greatest importance to a distinction which is most clearly evidenced in notions. Sir W. Hamilton is the latest exponent of this view.

Literature: historical notions of this distinction in HAMILTON, Discussions, App. II, and Logic, lect. viii; BAYNES, New Analytic of Logical Forms. All the larger treatises on logic, such as those of LOTZE and SIGWART, discuss the distinction. On the relative merits of extension and comprehension as basis of logical relations, see MILL, Exam. of Hamilton, chap. xxii; LANGE, Logische Stud. (1877); VENN, Symbolic Logic (2nd ed.), chap. xix; HUSSERL, in Vtljsch. f. wiss. Philos. (1891). (R.A.)

Extensity or Extensiveness (no fixed foreign equivalents, but those for EXTENSION; see below). An original spacial property supposed to attach to some or all sensations; also called voluminousness. (J.M.B., G.F.S.)

Stumpf uses Raum, räumliches (raumähnliches) Moment, Verbreitung des Eindrucks, Tongrösse, as well as (immanente) Ausdehnung. Stumpf, Ebbinghaus, and others use the adjectives massig, breit, uns rings umflutend, dünn, stechend, fein, spitzig, dick, voll, &c., to denote opposites of this 'extensity.' In Ital. estensività is suggested (E.M.).

Literature: JAMES (a 'feeling of crude extensity,' 'discernible in each and every sensation, though more developed in some than in others, is the original sensation of space.' It is clearest in sensations of 'hearing, touch, sight, and pain'), Princ. of Psychol., ii. 134-5; WARD, Encyc. Brit. (9th ed.), art. Psychology, 46; BAIN, Senses and Intellect (1868), 111, 199, 227; STUMPF, Raumvorstellung, 272, and Tonpsychologie, ii. 51; KÜLPE (a given attribute of sensations of sight and pressure; and areal extension, Ausgedehntheit), Outlines of Psychol., 30; J. MÜLLER (connate areal vision), Physiol. d. Gesichtssinnes, 56, 71. (E.B.T.)

Also H. TAINE, De l'Intelligence, ii. 81 ff. and 128 f. (Eng. trans., On the Intelligence); CH. DUNAN, Théorie psychologique de l'espace, (1895). (L.M.)

Extensor Muscles: see FLEXOR AND EXTENSOR.

External and Internal: see EXTERNAL OBJECTS, and EXPERIENCE.

External Objects: Ger. Dinge (und Ereignisse) der Aussenwelt; Fr. objets extérieurs; Ital. oggetti esterni. Things and events presented in sense-perception considered as existing independently of the process by which they are perceived. As thus existing they are said to have externality. (G.F.S.- J.M.B.)

One of the oldest psychological theories of our perception of an external object is that of Hobbes. According to him, sensation and sense-perception are due to the resistance offered by the organism to change produced to an external impression. 'Seeing, therefore, there is in the whole organ, by reason of its own internal natural motion, some resistance or reaction against the motion which is propagated from the object to the innermost part of the organ, there is also in the same organ an endeavour opposite to the endeavour which proceeds from the object, so that when that endeavour inwards is the last action in the act of sense, then from the reaction, how little soever the duration of it be, a phantasm or idea hath its being, which by reason that the endeavour is now outwards, doth always appear as something situate within the organ' (Works, Molesworth's ed., i. 391). This may be regarded as the germ of theories such as those of Maine de Biran, Bain, and others, which lay main stress on the experience of resistance to motor activity. Berkeley, following Locke, insisted on the relative uncontrollableness of sensations as compared with the flow of ideas. He also brought into prominence the essential part played by fixity and uniformity in the order or occurrence of sensation. This line of thought was afterwards followed up by J. S. Mill in his celebrated chapter in the Examination of Hamilton, entitled 'Psychological Theory of the Perception of External Reality.' A suggestive restatement of this doctrine is given by H. Cornelius in his Psychologie als Erfahrungswissenschaft, 99-114 (1897). Cf. BELIEF, and EXTERNAL WORLD.

Literature: PIKLER, Psychol. of the Belief in Objective Existence, Pt. I; Objectiva capable of Presentation, 4 (1890); STOUT, Manual of Psychol.; CROOM ROBERTSON, in Mind, O.S., xvi. 100, republished in Philos. Remains, 465 ff. (1894). Other notable references are WARD, Encyc. Brit., art. Psychology, 55-7; BALDWIN, Feeling and Will, 160 ff., and art. in Mind, O.S. (1891); SPENCER, Princ. of Psychol., ii. Pt. VII. chaps. xvi-xviii; LIPPS, Seelenleben, chap. xix; JAMES, Princ. of Psychol., chap. xxi; ROYCE, Studies of Good and Evil, viii. 198 ff. (G.F.S.)

External World (cognition of): Ger. Erkenntniss einer Aussenwelt; Fr. connaissance du monde extérieur; Ital. percezione del mondo esterno. Cognition of external objects and events as interconnected in a unified system.

Merely perceptual consciousness is concerned only with isolated objects or groups of objects. The cognition of an external world develops gradually by a process of ideal construction; and this ideal construction is essentially a social function involving co-operative thinking and willing. For belief in the external, see BELIEF, and EXTERNAL OBJECTS.

Literature: see the titles under EXTERNAL OBJECTS; and especially HUME, Treatise, Pt. IV. § 2; MILL, Exam. of Hamilton; LIPPS, Grundthatsachen, §§ 410-51; ROYCE, Studies of Good and Evil, 198 f.; STOUT, Manual of Psychol. (G.F.S., J.M.B.)

Externality: see EXTERNAL OBJECTS.

Extirpation [Lat. extirpatio]: Ger. Abtragung, Extirpation; Fr. extirpation or avulsion (according to the case -- (Y.D.)); Ital. estirpazione. The experimental removal of some part of an organ (as of the brain) for the purpose of ascertaining the nature of the changes in function resulting from its removal. Cf. LOCALIZATION (cerebral). (H.H.)

Extra-mundane: see MUNDUS.

Extreme Cases: see SCIENTIFIC METHOD.


Eye-measurement. Sometimes used as translation of the German Augenmass. Measurement, &c., of VISUAL AREA (q.v.) is recommended in its stead. (J.M.B., H.M.)

Eye-movements: Ger. Augenbewegungen; Fr. mouvements de l'oeil; Ital. movimenti dell' occhio. The normal movements of the two eyes together under control of certain muscles. Cf. Eye under VISION. (J.M.B.)

Eye-movements are of psychological importance in certain connections. (1) Free movements are supposed, on Wundt's genetic theory of space-perception, to account for the general form of the monocular field of vision, and the perception of the position of objects within it (Wundt, Physiol. Psychol., 4th ed., ii. 130, 131). (2) Free movements along the compared lines are our chief means of measurement of visual areas, the phenomena of which accordingly fall under Weber's law: the measurement being, probably, in terms of the intensity of muscular and tendinous, perhaps of pseudo-articular, sensations (Wundt, op. cit., 131). See KINAESTHETIC SENSATION. (3) Normal asymmetry of movement in the horizontal and vertical directions is thought to explain certain optical illusions, e.g. the greater apparent height, as compared with the breadth, of a square, &c. (cf. Wundt, op. cit., 137, and Abhandl. d. kgl. sächs. Gesell. d. Wiss., xxiv. 2). (4) The movements of CONVERGENCE (q.v.) and ACCOMMODATION (q.v.) apparently constitute the primary basis of our judgment of depth or binocular perception of DISTANCE (q.v.) (Wundt, Physiol. Psychol., 197, 215; cf. Arrer, in Philos. Stud., xiii. 116; Hillebrand, in Zeitsch. f. Psychol., vii. 97, xvi. 71; Dixon, in Mind, N.S., iv. 195). (5) Eye-movements do not assist us to estimate extent of movement when there is no possibility of reference to a fixed point. In themselves, that is, they are little noticed; their function has become symbolic. Illusions of movement may arise from this fact (see Külpe, Outlines of Psychol., 362). (6) Involuntary eye-movements are disturbing factors in many optical investigations, e.g. in the determination of the sensibility of the fovea to colour. They are, further, the condition of Purkinje's dizziness.

The physiological investigation of eye-movements began with J. Müller (cf. Helmholtz, Physiol. Optik, 2nd ed., 668); the psychological with Herbart and Lotze (Helmholtz, op. cit., 739, 740). It should be noted that the psychological importance of eye-movements is still a matter of keen dispute.

Literature: see the titles given above, and under SPACE (perception of), and LOCAL SIGN. (E.B.T.)