DICTIONARY OF
PHILOSOPHY AND PSYCHOLOGY

Mosaic Theory (of vision): Ger. mosaische Theorie (des Sehens); Fr. théorie mosaïque (de la vue); Ital. teoria mosaicistica (della visione). A theory put forth by Johannes Müller to explain the vision of Arthropods possessed of compound eyes.

Insects, Crustaceans, and other Arthropods are provided with eyes having many facets, under which are grouped retinal elements surrounding a crystalline cone. According to the Mosaic theory, the whole image seen is made up of a number of minute points, corresponding to the facets, which combine to form one picture. According to the rival theory advocated by Gottsche and others, each element of the compound eye yields a small but complete image.

Literature: J. MÜLLER, Zur vergl. Physiol. d. Gesichtssinnes (1826); GOTTSCHE, Beitr. z. Anat. u. Physiol. d. Fliegen u. Krebse, Müller's Arch. (1852); J. LUBBOCK, The Senses of Animals (1888). (E.S.G.)

Motion [Lat. motus, moved]: Ger. Bewegung; Fr. mouvement; Ital. moto (on all the foreign equivalents, cf. MOVEMENT). From the point of view of physics, motion is change in the relative position of two bodies: but this, as Locke truly observes, is to translate and not to define, for 'change' and 'position' already involve the idea of motion, which cannot in strictness be defined, but only exhibited in concrete experience. Motion involves the ideas of space and time, between which it seems in a sense to mediate. We measure space by the time which a body takes to move from one part of space to another. In doing so our ultimate standard of time is 'the constant and regular succession of ideas in a waking man' (Locke, Essay, ii. 14, II); but a convenient objective measure of time is subsequently found in certain uniformly recurring spatial movements, such as those of the earth and the sun.

The part of physics which deals with the theory of motion in its purely geometrical aspect is called kinematics. 'When the mutual action between bodies is taken into account, the science of motion is called KINETICS (q.v.), and when special attention is paid to force as the cause of motion, it is called DYNAMICS' (q.v.) (Clerk Maxwell, Matter and Motion, art. 36).

Heraclitus is the first philosopher to insist on the fact of movement as constituting the most characteristic aspect of the universe; but he is content to state the general fact of change or process without distinguishing its different forms. Treating it, moreover, as an ultimate fact, he does not inquire into the cause of motion (oqen h arch thV kinhsewV). The Eleatics, on the other hand, treated the fact of motion as an illusory appearance, and the arguments of ZENO (q.v.) against its possibility -- founded chiefly upon the infinite divisibility of space -- are among the best known pieces of ancient dialectic. The Atomists, by reducing all change to movement of the atoms in empty space, were the first to formulate the modern physical conception of motion. They conceived this motion as eternal, and found it sufficiently explained by the fall of the atoms through infinite space. Empedocles sought a cause of motion in the mythical forces of love and hate; and Anaxagoras, by tracing it to the action of nouV, or mind, made an epoch in Greek philosophy, even though mind was conceived by him quasi-materialistically as communicating a mechanical impact to his atomic elements. The most instructive account of motion in ancient times is to be found in Aristotle, who sees in kinhsiV the most universal  characteristic of nature. Physics, as contrasted with First Philosophy, deals with existence not in itself, but in so far as it participates in kinhsiV. Taking kinhsiV in its widest sense, he distinguishes three varieties -- alloiwsiV, or qualitative change: auxhsiV kai fqisiV, quantitative increase or decrease; and h kata topon fora, or movement in space. Of these the last is the fundamental form, as involved in the others, but Aristotle does not, like the Atomists, reduce qualitative differences to purely quantitative relations of size and position. Aristotle teaches the eternity of motion, as he teaches the eternity of the world, but he seeks the explanation of motion in an eternal mover, itself unmoved (to prwton kinoun akinhtov, Physics, 8. 6, 258 B). This eternal principle of movement is God -- conceived, however, not mechanically (and therefore not materialistically) as with Anaxagoras, but teleologically, as the immanent end and real explanation of the whole world-process. This is known as Aristotle's doctrine of 'mover and moved.'

The most recent philosophy still presents the same conflict between what may be called the Democritic and the Aristotelian -- the mechanical and the teleological point of view. The modern mechanical theory, substituting gravitation for the 'fall' of the atoms, would reduce the world to a physical problem of the continual redistribution of matter and motion. But gravitation is after all a law rather than a force; and like all scientific laws, it furnishes us with a generalized description of what happens, but does not (at least, ought not to) profess to explain these happenings in the sense of assigning their true cause. The opposite view is that the true cause or ultimate explanation of any process always involves the conception of end; as Aristotle insists, the end, though apparently the last resultant, is first in the order of real existence.

Descartes' doctrine that the quantity of motion in the universe is constant, and the controversies to which it gave rise, belong to the history of physics rather than to that of philosophy. Cf. CONSERVATION, ENERGY, PHORONOMY, and ACTIVITY. (A.S.P.P.)

Motion (illusions of): see ILLUSIONS OF MOTION AND MOVEMENT, I.

Motion and Rest (in physics): Ger. Bewegung und Ruhe; Fr. mouvement et repos; Ital. moto e riposo. Motion is change of place; a phenomenon too familiar to need detailed definition. See MOTION. Rest is absence of motion.

Motion has two properties: --

(1) It is continuous: no body changes its position from a point A to another point B except by passing through an unbroken series of intermediate positions, which, if the body is regarded as a point, will form a line.

(2) Motion can be apprehended only as relative. In space itself there is no such thing as sameness of position. Position can be defined only with respect to the position of a body. Given one such body, and only one, there will be no way of determining whether it is in motion or at rest. Given two bodies, either may be in motion relative to the other; but of neither can we say that it is in motion or at rest when considered by itself. Motions on the earth's surface are familiarly conceived with reference to that surface. But the earth itself is in motion on its axis, and this axis moves around the sun. Thus motions around us are very different when we refer them to the earth's centre, or to the sun. The sun itself is in motion relative to the other stars, and thus we may have another link in the chain, the end of which we cannot conceive. (S.N.)

Motive [Lat. motus, from movere, to move]: Ger. Motiv; Fr. motif, mobile (AFFECT, q.v.); Ital. motivo. (1) Any conscious element considered as entering into the determination of a volition.

(2) Any conscious END (q.v.) considered as entering into the determination of a volition.

The first definition is better and is recommended, principally for the reason that the term end is sufficient to express the second meaning. There is great confusion of the two meanings with each other. The second usage arises from the attempt to prove that all motives are intellectual, and of the nature of ends. There is need, however, for a term of the wider signification; and the division of ends from other motives, in the first sense, may be marked by the term AFFECT (q.v.), as is recommended under that topic. Affects are the motives, however uncognized and affective -- such as organic sensations, vital sensations, dispositions of an emotional or conative sort, &c. -- which do not have the character of presentation in idea. They also include the negative determining or limiting (massgebende, Wundt) conditions of a voluntary decision. Ends, on the other hand, are the motives which do have the character of presentation in idea.

The broader definition (1) had early statement in Bentham (Introd. to the Princ. of Mor. and Legisl., 1789, chap. x. § 1), i.e. 'Anything that can contribute to give birth to, or even to present, any kind of action,' or 'Anything whatsoever which, by influencing the will of a sensitive being, is supposed to serve as a means of determining him to act, or voluntarily to forbear to act, upon any occasion.' (J.M.B.- G.F.S.)

When two or more ends are presented as desirable, either simultaneously or in immediately succeeding states of consciousness, we have the experience known as 'conflict of motives,' the conflict being terminated by a voluntary decision or choice. The denial of the appropriateness of the term 'conflict of motives' is due to the limitation of the term 'motive' to an experience in which the motive actually issues in action -- a limitation which appears to be an unnecessary restriction of the prevailing use of the term. The term 'controlling motive,' applied to that motive to which the decision most nearly conforms, is unfortunate, since it is difficult to say what it controls, and also since the course chosen is rarely true to any one of the alternative motives. (W.R.S.- J.M.B.)

Literature: the textbooks of psychology and ethics. For the distinction between the two definitions see citations under AFFECT. Cf. STOUT, Manual of Psychol., Bk. IV. chap. x; D. G. RITCHIE and others in Int. J. of Ethics, iv. 89, 229. A notable discussion from the point of view of the second definition is that of GREEN, Prolegomena to Ethics, Bk. II. chap. i. (J.M.B.- W.R.S.)

Motor [Lat. motum, from movere, to move]: Ger. motorisch; Fr. moteur; Ital. motore. Pertaining to the apparatus and consciousness of action.

The term is opposed to sensory, which is applied to the apparatus and consciousness of the reception of experience. Motor is used in various phrases, such as VASO-MOTOR (q.v.), 'motor consciousness,' 'motor reaction.' It characterizes also the type of psychological theories which explain complex mental products more or less in terms of 'motor elements' (i.e. sensations from muscular and physiological movements), and of conations. See MOVEMENT, and cf. SENSORY AND MOTOR ELEMENTS. (J.M.B., G.F.S.)

Motor Intuition: see INTUITION (in psychology).

Motor Type: see TYPE (mental).

Movement [Lat. movere, to move]: Ger. Bewegung (used also for motion); Fr. mouvement; Ital. movimento. (1) Motion of any sort.

(2) Organic action; cf. MOVEMENT (in physiology).

(3) Action of the motor apparatus.

There is great confusion as between these meanings in all the languages cited. Movement is used (1) in the broadest possible sense to cover mechanical motion. But there is a distinct tendency to restrict the term motion to the mechanical, and to use movement (2) for the action of organisms, in which vital or psychological processes complicate the phenomena. The further restriction contained in definition (3) has arisen in psychology, where the distinction between the motor and the sensory processes, and their correlative psychological states, has made the term movement in this sense convenient. On the whole, it is safe to recommend that the term be restricted in psychology to meaning (3); that, nevertheless, its use in sense (2) be recognized in physiological discussions; but that, so far as possible, the distinction between movement and motion be observed, the latter having exclusive application to the objective phenomena of change of place. For example, I make a movement of my arm; but I observe by sight the motion of a bird through the air. For the midway cases of one's observation of his own movement, the term movement is preferable, as in the phrases 'movement sensations,' 'illusions of movement,' &c.; yet when these are classified with other phenomena of motion, the latter term should be applied to them.

Psychological theories in the realm of movement are largely concerned with the formulations respecting conation -- with reflexes, instincts, and voluntary determinations -- on the side of consciousness; and with those of reaction, dynamogenesis, theory of kinaesthetic sensations and equivalents, on the side of the organism; together with the motor and 'action' theories, which assign to elements of motor content -- attitudes, dispositions, habits, accommodations, &c. -- important rôles in mental development. The discussions of effort, fatigue, and emotional expression, and the investigations into the localization of the motor areas of the brain cortex, have emphasized the tendency to make active accommodation and its requirements at least as essential as are the cognitive and receptive functions -- a point of view quite undeveloped until this generation. The two sides of the mental life, however, are more sharply distinguished for the purposes of theory than from any fundamental difference of kind; for the movement elements are throughout sensational in their origin, and accordingly the reduction of the motor to the sensory continuum seems to be legitimate. The theoretical question then concerns the determination of the sensational elements -- muscular and kinaesthetic -- which, in their function as determining motor accommodation and control, minister to the progress of the mental life. This is where motor or action theories get their value; and it is being fully recognized in current discussion.

The analysis of a given movement function, of which HANDWRITING (q.v.) may be taken as a good example, results in the establishment of certain factors: (1) a 'copy series,' which is held up to be reproduced. (2) The acquisition, by a process of selection through experimentation, of the series of kinaesthetic equivalents required for reproducing the 'copy-series'; this we suggest calling the 'efficient series.' (3) The association of the efficient series with any 'remote' sensation series (cf. KINAESTHETIC SENSATION) which enters into the accomplished movement. (4) The establishment of a 'control series,' by which the efficient series is, term by term, held to its proper course in each successive performance of the movement. Of these elements the first is not kinaesthetic, but is a copy presented by sight, hearing, or other sense, to the reproduction of which the muscular apparatus is made to bend its energies. The second, the efficient, is gradually brought into conformity with the copy. The third comes to take the place of the copy, so that short-cuts are established, allowing the performance of the movement without the original copy-series. The fourth is found in that one -- or all -- of the series in question which stands to check and guide the performance of the movement. It establishes what is called the control of a movement, and may be looked at a little more closely.

The phenomenon of muscular performance with control seems to have two elements, more or less distinct from each other: release and actual control. The release is found in the conscious 'equivalent,' of the kinaesthetic order, which, when held in the attention, serves as preparation for the voluntary execution of the efficient series. Without attention successfully given to the equivalent the movement is impossible; this is shown in cases of patients who cannot move a limb unless that limb be seen -- the equivalent being visual. The control, on the other hand, is not essential to the movement, but regulates it. It consists of the holding in the attention, together with the efficient series, of a secondary or auxiliary series, seen negatively in handwriting with the eyes closed: the hand goes astray, because of the absence of the optical perception of the letters as they are made. This latter, when present, acts as control in the progress of the writing, although without it writing of an irregular and unformed kind is still possible.

The most adequate theory of the mechanism of control makes it a function of attention, which effects a synthesis of all the elements necessary for the perfected movement; certain more important series, however, taking the lead in this case or that. Interesting differences among individuals are brought out in pathological cases: to some, from their mental type, habit of performance, or emphasis in learning, one series is more necessary; to some another, in the performance of the same motor function. Furthermore, there is the fact of progressive automatization of function in the matter of control, as elsewhere. Such a semi-automatic performance starts with the same release; but the attention is given not to the details of the successive stages of the action, but to the act as a whole. In these cases, the attempt to control the movements by giving attention to the individual terms of the control series delays and disturbs the action.

See, besides the various topics mentioned, MUSCLE, ILLUSIONS OF MOTION AND MOVEMENT, and SYNERGY.

Literature: the textbooks of psychology, and the citations made under the various topics indicated; also BIBLIOG. G, 2, p, et al. On muscular control see under HANDWRITING; also JANET, Automatisme psychol.; PICK, Zeitsch. f. Psychol., iv. (1892) 161; and in general the literature of the various motor processes and of ATTENTION. Distinctively 'motor' or 'action' theories are developed in the works of MÜNSTERBERG (see the résumé in Grundz. d. Psychol., i. chap. xv, with literature); FOUILLÉE, Les Idées-Forces; STOUT, Manual of Psychol.; BALDWIN, Ment. Devel. (2 vols.). (J.M.B., G.F.S.)

Movement (disorders of). Disorders of movement may be due to irregularities in (1) the execution or control of the action, or in (2) the relation of the action to its motive impulse. The former constitute true motor disorders; the latter are of the nature of affections of the will, impairing action. See WILL (disorders of).

(1) True movement or motor disorders of psychological interest may be grouped as (a) inability to execute (certain types of) movement or their imperfect and difficult execution owing to an impaired co-ordination; and as (b) inability to restrain or control (certain types of) movement. The former groups includes paralyses and pareses, contractures, ataxias, &c.; the latter tremors, spasms, convulsions, movement-habits (choreic movements, tics, &c.). The movements thus considered are in most part of a voluntary type; but disorders of reflex and automatic movements also occur. Such conditions as rigidity, flexibitias carea, catalepsy, illustrate abnormal motor symptoms, in which a psychic element is prominent. The physiological and medical aspect of motor disorders is concerned with their relations to degenerations and irritations in spinal and higher nervous centres, to diseases of nerve and muscle tissues, and to defective nutritional conditions.

The detailed and systematic account of the nature of motor disorders is to be found in the standard works on diseases of the nervous system; they are there treated as symptoms in connection with organic and functional disabilities of nerve and nerve-centre; special attention is given to the differential diagnosis of motor affections resulting from peripheral and from central defect, and again to the correlation of the symptom-complex with the specific grade of centre involved (cortical, spinal, &c.). PARALYSIS (q.v.), for instance, is a most common symptom of disease of the peripheral nervous system, but may be the result of lesion of brain or cord. A paralysis affecting the distribution of one nerve, and completely so, and depriving the muscle of its tone, thus producing a flaccid palsy (without secondary contracture), is recognized as of peripheral origin. Paralyses of cortical origin have other characteristic differentia.

A group of neuroses in which the motor disorders form the most conspicuous symptoms are sometimes termed spasmodic neuroses. They include chorea, with its convulsive movements, contortions, tremors, &c.; tetanus, with its characteristic contracture, facial and other local spasms, the professional neuroses, such as writer's cramp, the convulsive tics and motor habits which often exhibit sensitiveness to contagion and suggestion. The inco-ordinations of speech seen in stuttering, the ataxic symptoms of tabes, the epileptic fit, the spasms and convulsions of hysteria, the motor affections due to alcohol or other poisons, illustrate the range and variety of motor defects. See the various terms cited. (J.J.)

Movement (illusions of): see ILLUSIONS OF MOTION AND MOVEMENT, II.

Movement (in physiology): Ger. Bewegung; Fr. mouvement; Ital. movimento. Change of form of cells or organs brought about by power inherent in a tissue to rearrange its particles; as amoeboid movement: that resembling the changes of form of an amoeba; ciliary movement, muscular movement (see MUSCLE, and cf. MOVEMENT, 2, 3). (C.F.H.)

Movement and Motion (experiments on). The following are the chief topics of experimentation upon MOVEMENT (q.v.) and MOTION (q.v.). Cf. LABORATORY AND APPARATUS, II, A, B, (c) (3-5).

(1) Movement and its perception. (a) Liminal (least perceptible) movement. The various joints differ considerably in the extent of the least perceptible passive movement; for the forefinger the threshold is 1.03^o - 1.26^o; wrist, .26^o - 42^o ; elbow, .40^o - .61^o; shoulder, .22^o - .42^o (Goldscheider, Arch. f. Physiol., 1889, 486); the thresholds for active and passive movement are about equal (ibid., 1889, Suppl. - Bd., 141); a slower rate of movement raises the threshold (ibid., 1889, 369). See also EYE-MOVEMENTS. (b) Comparison of movements: repetition of movement with same hand or arm, to determine least perceptible difference in extent; relations of extent between movements of the two arms (either successive or simultaneous); relations of symmetry and form between simultaneous movements of the two arms. Cf. Loeb, Pflüger's Arch., x1i. (1887) 107; x1vi. (1890) 1-46; Hall and Hartwell, Mind, ix (1884), 93; Münsterberg, Beitr. z. exper. Psychol., Heft iii. 65, Heft iv. 192; Baldwin, in Science (1890). (c) ILLUSIONS OF MOTION AND MOVEMENT (q.v.).

(2) Motion and its perception. The motion of an object is most frequently judged by comparison with some subjective movement, e.g. following it with the eye (cf. EYE-MOVEMENTS). In special cases the two are separated: (a) Motion upon the skin when the member is at rest; experiments here include least perceptible distance (on various parts of the body), judgment of direction, judgment of rate, comparison of different distances. Cf. Hall and Donaldson, Mind, x. (1885) 551; Tawney and Hodge, Psychol. Rev., iv. 591. (b) Motion of the body as a whole, progressive or rotary; direct perception is here limited to change of rate; in rotary motion, the least perceptible change is about 5^o per second. Cf. Mach, Grundlinien d. Lehre v. d. Bewegungsempfindung; Warren, Psychol. Rev., ii. 273. See ILLUSIONS OF MOTION AND MOVEMENT.

(3) Execution of voluntary movement. (a) Time. See REACTION TIME. (b) Precision; effect of practice; 'cross-education,' e.g. gain of precision with one arm as a result of practice with the other. Cf. Scripture, Smith, and Brown, Yale Stud., ii. 114. (c) Rate. Cf. Galton, Rep. Anthropom. Lab., 1885; Fullerton and Cattell, On the Perception of Small Differences(1892). (d) Force; adjustment of motor discharge to expected resistance. Cf. Müller and Schumann, Pflüger's Arch., (1891), 119; Delabarre, Ueber Bewegungsempfindungen (1891); Fullerton and Cattel, loc. cit.; Delabarre, Logan, and Reed, Psychol. Rev., iv (1897), 615. (e) FATIGUE (q.v.). (f) Passage of voluntary into automatic movement. Cf. Solomons and Stein, Psychol. Rev., iii. 492, and v. 295; the literature given under HABIT and REACTION TIME (effects of practice).

(4) Involuntary movements. (a) Reflexes (knee-jerk, &c.). See REFLEX, and PATELLAR REFLEX. (b) Tremor of hand. See Jastrow, Amer. J. of Psychol., iv, v; Tucker, ibid., viii. (c) Accommodation and convergence. Cf. EYE-MOVEMENTS. (d) Jerking of eyes. Cf. EYE-MOVEMENTS. (e) Motor expression of emotion. Cf. EMOTIONAL EXPRESSION. (H.C.W.)

Mover and Moved (in Aristotle): see MOTION, passim, and PRIMUM MOBILE.

Müller, Friedrich Max. (1823-1900.) Born at Dessau, Germany; educated at Leipzig and Berlin Universities. Settled at Oxford in 1848, and became professor of comparative philology in Oxford University in 1868. His fame was principally as a philologist and orientalist, although he wrote also on philosophical and psychological topics.

Müller's Circle: Ger. Müller'scher Kreis; Fr. cercle de Müller; Ital. circolo del Müller. A circle which passes through the fixation point and the optical centres of the two eyes, and which lies in the plane of regard when the eyes are in the primary position of convergence. Cf. HOROPTER. (E.B.T.)

Multiplicity: Ger. Vielheit, Mannigfaltigkeit; Fr. multiplicité; Ital. moltiplicità. This term appears in connection with the problem of the One and the Many which so early agitated Greek philosophy. How, that is to say, are we to reconcile the aspect of the world as consisting of an apparently infinite number of separate beings with the unity of existence which philosophic reason demands? Cf. ONE (the), and UNITY AND PLURALITY.

The Eleatic philosophy pronounced the appearance of multiplicity to be an illusion of the senses; and Zeno, by a series of indirect arguments, endeavours to demonstrate its impossibility. The same problem (en ta polla einai kai to en polla) reappears in Plato, who reduces the multiplicity of sense-phenomena to the unity of the idea in which they participate or which they represent. The multiplicity of the sense-world appears to be regarded here also as a species of illusion. But Plato recognizes a multiplicity within the ideal world itself, in virtue of what has been called the community of concepts (koinwnia twn genwn), or the participation of the ideas in one another. This world of ideas thus differs from the abstract unity of the Eleatics in being rather a series of ideas which dialectically imply one another. As he says in the Philebus (15 D): 'The One and the Many run about everywhere together, in and out of every word which is uttered, as they have done in all time past as well as present; and this union of them will never cease, and is not now beginning, but is, I believe, an everlasting quality of thought itself, which never grows old in us.'

The same question of the One and the Many is the underlying motive of the scholastic disputes between nominalism and realism, and gives a pantheistic or an individualistic bias to the systems of most philosophers.

In the Kantian philosophy, the contribution of sense to knowledge is spoken of as a mere Manifold (Mannigfaltiges), a multiplicity or diversity of particulars. The synthetic function of the understanding must supervene with its categories or connective notions upon these passively apprehended units of sense before we can speak of knowledge or experience. (A.S.P.P.)

Multitude (in mathematics) [Lat. multitudo]: Ger. Mächtigkeit, Cardinalzahl; Fr. puissance; Ital. moltitudine. That relative character of a collection which makes it greater than some collections and less than others. A collection, say that of the A's, is greater than another, say that of the B's, if, and only if, it is impossible that there should be any relation r, such that every A stands in the relation r to a B to which no other A is in the relation r.

The precise analysis of the notion is due to G. Cantor, whose definition is, however, a little different in its mode of expression, since it is more abstract. He defines the character in these words: 'By Mächtigkeit or cardinal number of a collection (Menge) M, we mean the universal concept, which by the help of our active faculty of thought results from the collection M by abstraction from the characters of the different members (Elemente) of that collection and from the order in which they are given (Gegebensein).

A cardinal number, though confounded with multitude by Cantor, is in fact one of a series of vocables the prime purpose of which, quite unlike any other words, is to serve as an instrument in the performance of the experiment of counting; these numbers being pronounced in their order from the beginning, one as each member of the collection is disposed of in the operation of counting. If the operation comes to an end by the exhaustion of the collection, the last cardinal number pronounced is applied adjectivally to the collection, and expresses its multitude, by virtue of the theorem that a collection the counting of which comes to an end, always comes to an end with the pronunciation of the same cardinal number.

If the cardinal numbers are considered abstractedly from their use in counting, simply in themselves, as objects of mathematical reasoning, stripped of all accidents not pertinent to such study, they become  indistinguishable from the similarly treated ordinal numbers, and are then usually called ordinal numbers by the mathematico-logicians. There is small objection to this; yet it is to be remarked that they are ordinal in different senses in grammar and in the logic of mathematics. For in grammar they are called ordinal as being adapted to express the ordinal places of other things in the series to which those things belong; while in the logic of mathematics the only relevant sense in which they are ordinal is as being defined by a serial order within their own system. The definition of this order is not difficult; but the syntax of ordinary language does not lend itself to the clear expression of such relations in the manner in which they ought to be expressed in order to bring out their logical character. It must, therefore, be here passed by. In fact, none of the doctrines of logic can be satisfactorily expressed under the limitations here imposed, however simple they may be. The doctrine of ordinal numbers is by Dedekind (Was sind und was sollen die Zahlen?) made to precede that of the cardinal numbers; and this is logically preferable, if hardly so imperative as Schröder considers it.

The doctrine of the so-called ordinal numbers is a doctrine of pure mathematics; the doctrine of cardinal numbers, or, rather, of multitude, is a doctrine of mathematics applied to logic. The smallest multitude is most conveniently considered to be zero; but this is a question of definition. A finite collection is one of which the syllogism of transposed quantity holds good. Of finite collections, it is true that the whole is greater than any part. It is singular that this is often taken as the type of an axiom, although it has from early times been a matter of familiar knowledge that it is not true of infinite collections. Every addition of one increases a finite multitude. An infinite collection cannot be separated into a lesser collection of parts all smaller than itself.

The multitude of all the different finite multitudes is the smallest infinite multitude. It is called the denumeral multitude. (Cantor uses a word equivalent to denumerable; but the other form has the advantage of being differentiated from words like enumerable, abnumerable, which denote classes of multitudes, not, like denumeral, a single multitude.) Following upon this is a denumeral series of multitudes called by C. S. Peirce the first, second, &c. abnumerable multitudes. Each is the multitude of possible collections formed from the members of a collection of the next preceding multitude. They seem to be the same multitudes that are denoted by Cantor as Alephs. The first of them is the multitude of different limits of possible convergent series of rational fractions, and therefore of all the quantities with which mathematical analysis can deal under the limitations of the doctrine of limits. (The imaginaries do not increase the multitude.) What comes after these is still a matter of dispute, and is perhaps of inferior interest. The transition to continuity is, however, a matter of supreme importance for the theory of scientific method; nor is it a very complicated matter; but it cannot be stated under the limitations of expression here imposed upon us. (C.S.P., H.B.F.)

Literature: see NUMBER.

Mundane: see MUNDUS.

Mundus [Lat.]: Ger. Welt; Fr. monde; Ital. mondo. The term used by the Romans to render the Greek kosmoV, the visible orderly system of the world, with more particular reference to the heavens and the heavenly bodies, whose regular motions first impressed the idea of order on primitive thought.

Cicero's definition (Tim. 10) retains this reference: 'ut hunc hac varietate distinctum bene Graeci kosmon, nos lucentem mundum nominaremus.' In so far as this system is contrasted with a preceding state of things -- whether chaos or primitive elements -- the kosmoV or mundus is regarded as limited both in time and in space, and is not therefore to be identified with the universe (to pan, omne). The Epicurean philosophy in particular supposes innumerable worlds (in some respects perhaps resembling, in many more probably differing from, the world-system we know) to result from the mechanical clashings of the atoms in infinite space throughout infinite time. Each world-system is girdled from the embrace of hungry space by an outer envelope of fire or ether -- the 'flammantia moenia mundi' of Lucretius' account. In the 'intermundia' or intermundane spaces Epicurus supposed the gods to reside. Cf. Lucretius, De rerum Natura, iii. 16-22, finely rendered by Tennyson in his poem Lucretius.

The terms mundus sensibilis and mundus intelligibilis were used to express the Platonic contrast between the world of sense-perception, which is a world of phenomena or mere appearance, and the ideal world, the world of noumena or of ultimate reality. They were appropriated by Kant, in a somewhat altered sense, to denote the world of nature or of categorized sensation, to which he limits our knowledge; and the intelligible world (Verstandeswelt), which is for the theoretic reason a merely negative or limitative conception, but which the practical reason reveals as a realm of ethical ends and moral freedom. It is in connection with this Kantian distinction that the term mostly occurs in modern philosophical writing. (A.S.P.P.)

Mundane and extra-mundane are used respectively for what is and what is not subject to the conditions of the physical world. (H.R.S.)

Muscae Volitantes [Lat. musca, a fly, + volitans, dancing]; Ger. fliegende Mücken; Fr. mouches volantes; Ital. mosche volanti. Variable entoptic appearances, due to the presence of small foreign bodies in the vitreous humour. They take the form of bright worm-like threads, strings of glistening beads, groups of bright dots, tiny circles with brighter centres, &c., and usually travel downward in the field of vision (i.e. upward in the humour). Cf. ENTOPTIC PHENOMENA.

Literature: HELMHOLTZ, Physiol. Optik. (2nd ed.) 188; SANFORD, Course in Exper. Psychol., expt. 110. (E.B.T.)

Muscle [Lat. musculus, little mouse, dim. of mus, Gr. muV]: Ger. Muskel; Fr. muscle; Ital. muscolo. The active movements of animals are accomplished by means of a specially differentiated contractile tissue called muscle.

Contractility is a general property of living organisms manifested in amoeboid, ciliary, or muscular movements. Even in the unicellular Protozoa, certain portions of the cell-substance become specialized as contractile fibrils for executing movements, and in the lower Metazoa, such as the Coelentera (Polyps and Jelly-fish), cells of the outer and of the inner epithelium may develop special contractile basal processes. The muscular movements of the Coelomata are accomplished by means of special muscle-cells, or cross-striated muscle-fibres, developed from the mesodermal layer of the EMBRYO (q.v.). Muscle-cells chiefly are found in Worms, Molluscs, and Echinoderms; striated muscle-fibres in Arthropods. In the higher vertebrates, such as man, the 'smooth' muscle-cells are found in the walls of the intestine and the viscera, and of the blood-vessels. Their contraction is not under the direct control of the will, hence they are frequently called the involuntary muscular tissue. These muscles are formed of elongated cells pointed at both ends, consisting chiefly of longitudinally striated contractile substance, enclosed in a delicate sheath, and provided with an oval nucleus. The muscles of the heart are composed of peculiar fibres made of rows of flattened, more or less branched, cells exhibiting transverse striations. The voluntary or skeletal muscles, the contraction of which is under the direct control of the will, constitute by far the greater part of the muscular or fleshy portions of the body, and consist of cross-striated fibres.

The fibres are formed of a thin sheath (sarcolemma) enclosing the elongated, more or less cylindrical, soft muscular substance provided with numerous oval nuclei at its periphery. Under the microscope the muscular substance exhibits fine longitudinal and coarse transverse striations. The former seem to be due to the fact that each fibre is formed of a bundle of fine parallel fibrils (sarcostyles); whilst the cross striae are due to the alternation of narrow light with broader and more opaque regions. The denser and firmer substance of the sarcostyles appears to be the more actively contractile element, embedded in the more fluid substance (sarcoplasm) accumulated in the region of the light-zones. Contraction of the fibre is brought about by the shortening and swelling of the row of segments of the sarcostyles occupying the dark zones. Waves of contraction may pass along the fibre.

Muscles are formed of bundles of such fibres bound together in connective tissue and extending from one point of attachment to another. Movement of the parts is brought about by a drawing together of the points of attachment when the muscle contracts, portions of the bony skeleton often serving as levers.

The energy required for the muscular contractions is derived partly from carbohydrates, such as glycogen, stored in the muscle itself or brought to it by the blood, and probably also from fats.

Living muscle is very elastic and extensible. During contraction it shortens and becomes correspondingly thicker. On relaxation it reverts to its original shape by virtue of its elasticity. Normally, a muscle contracts on receiving a stimulus through its motor nerve; but it may be made to contract by the application of suitable mechanical, electrical, thermal, or chemical stimuli, either directly or indirectly by means of its nerve. A single stimulus causes a single 'twitch' of the muscle; the contraction is preceded by a very short 'latent period,' and is followed by a longer period of relaxation. On repeating the stimulus, the contractions at first slightly increase in strength, then begin to decrease, and steadily diminish, until finally the muscle reacts no more. This muscular 'fatigue' is due probably both to the accumulation of waste products and to the exhaustion of the materials which afford the source of energy. Within certain limits, the contraction of a muscle is proportional to the strength of the stimulus, being nil with less than minimal stimulus, and constant after the stimulus has reached its maximal intensity. A repetition of stimuli following each other so rapidly that the muscle has no time to relax, leads to the condition known as 'tetanus,' in which the muscle remains in a state of contraction until the stimulus cease or it is exhausted. Persistent voluntary contractions are considered by some physiologists to be of the nature of a tetanus.

Literature: E. A. SCHÄFER, Essentials of Histology, also in Quain's Anat. (10th ed.); textbooks of physiology, e.g. FOSTER'S, WALLER'S, 'American,' &c. For a full table of the human muscles, with figures, see GOULD, Illus. Dict. of Med., sub verbo. (E.S.G.)

Muscle Reading: Ger. Muckellesen, Gedankenlesen (thought reading); Fr. lecture de la pensée (thought reading); Ital. lettura del pensiero (thought reading). The interpretation through contact, such as grasping the hand, of slight involuntary movements or muscular contractions, and the detection thereby of the direction or object of another's thoughts.

The basis of muscle reading rests upon the tendency -- a marked one in some individuals, and less so in others -- of involuntary movements and impulses to motor expression to accompany mental operations. Such movements find most ready expression in the contraction of delicate and specialized muscle groups, of which the hand is a familiar example. Such involuntary movements, particularly of the hand, were offered in explanation of the phenomena of spiritualism, such as the rappings, table turning, and planchette writing. The phenomena of the divining rod have also been referred to involuntary movements (see letter of Chevreul, 1852, in Binet, Alterations of Personality, Eng. trans., 221). The experimental demonstration of these movements has been frequently made. For such purpose an apparatus is necessary by which the movements may be rendered visible. Such apparatus have been devised by Jastrow (Fact and Fable in Psychol., 130) and Sommer (Zeitsch. f. Psychol., xvi. 275). See Automatograph, under LABORATORY AND APPARATUS, II, B, (c), (5).

In this way it has been proved that the thought of a particular corner of the room is likely involuntarily to direct the hand towards that corner, the direction of the attention towards a sound is apt to start a movement towards the locality of the sound, and so on. In brief, the local direction of the attention is more or less readily reflected in the accompanying involuntary movement. More recently it has been shown that involuntary whispering may also occur; and the movements of the larynx accompanying reading to oneself, the active thinking of certain sounds, &c., have been recorded. While the mere fact of movement not infrequently rises into consciousness, the directions and details of the movements remain unconscious and wholly involuntary. When, in susceptible persons, these movements become pronounced and directive, they develop into AUTOMATIC WRITING (q.v.), planchette writing, &c. Ordinarily the movements fundamental to muscle reading involve only direction and local indication; but truly 'automatic' movements convey by symbols, such as writing, an indication of the content of the mover's thoughts.

Muscle reading as an expert performance has been exhibited by various performers from about 1874; it is often misleadingly termed mind reading and heralded as dependent upon a mysterious power to divine another's thoughts. The usual procedure is for the muscle reader to place the hand of his subject against his own forehead, and by noting the indications of the movements and of their direction and the moments of increased excitement, to find a hidden object, to select from a group of numbers the digits which compose the number of a bank-note of which the subject is thinking, and other more elaborate variations of such procedures. The skill with which such involuntary indications can be interpreted by an expert muscle reader -- combined with a more general shrewdness and altertness -- is remarkable, and many striking feats have been recorded. It may be stated as probable that, apart from general shrewdness, such performances (feats involving collusion or fraud are not considered in this connection) involve nothing more than the skilful interpretations of involuntary muscular contractions; but with this must be included not only definite movements, but exhibition of excitement (change of respiration, flushing, the hush of the audience when the muscle reader approaches the hiding-place, &c.), and all the various accompaniments of intense concentration. The process on the part of the muscle reader requires an extreme and wearing concentration, and some performers are only dimly conscious of their modus operandi. The difference in the readiness with which various subjects become helpful to a muscle reader is very great; but nothing more than general correlations of such motor tendencies with other nervous dispositions may be postulated.

We may name Cumberland, Bishop, Brown, Onofroff, Capper, Pikman, Dalton, Caselli, and others as expert performers.

Literature: (on involuntary movements): JASTROW, Amer. J. of Psychol., iv. (1892) 398 ff., v. (1892) 223 ff.; PREYER, Die Erklärung des Gedankenlesens (1886); HANSEN and LEHMANN, Ueber unwillkürliches Flüstern, Philos. Stud., xi. (1895) 471-530; CURTIS, Automatic Movements of Larynx, Amer. J. of Psychol., xi. (1900) 237-40. On muscle-reading performances: articles on Muscle Reading, Mind Reading, or Thought Reading, in Nineteenth Cent., xx. 867; Forum, xi. 192; Pop. Sci. Mo., x. 459, xxi. 634 (Beard); Annual Encyc. (1887), 506. (J.J.)

On 'Pikmanism' or 'Cumberlandism' see articles by MORSELLI, TAMBURINI, GUICCIARDI, and FERRARI, in Riv. Sperim. di Freniat. (1891-9). See also OTTOLENGHI, La Suggestione e la Facoltà psichiche occulte (1900), 95-139; BEARD, The Study of Trance, Muscle Reading, &c. (New York, 1882); TARCHANOFF, Gedankenlesen (1895). (E.M.)

Muscle-sense and Muscle-sense Illusions: see MUSCULAR SENSATION, and ILLUSIONS OF MOTION AND MOVEMENT, II.

Muscular (or Muscle) Sensation: Ger. Muskelempfindung; Fr. sensation musculaire; Ital. sensazione muscolare. The phrase is used, loosely and vaguely, for (1) the complex of sensations arising from skin, joint, muscle, and tendon in such perceptions as those of resistance, of movement, and of lifted weight. It is thus the equivalent of Bastian's KINAESTHETIC SENSATION (q.v.).; and for (2) a sensation of dull and diffused character obtained (after elimination of other sense-qualities) by stimulation of a striped muscle; localized, like articular sensation, within the stimulated limb. (E.B.T.- J.M.B.)

(3) A sensation of muscular fatigue which follows long-continued stimulation of a muscle, either voluntary (indirect) or non-voluntary (direct: electrical, chemical, &c.).

It is probable that muscular fatigue is a congeries of mixed qualities of the preceding sorts, (1) and (2). The question of its central or peripheral seat is now about settled in favour of the kinaesthetic view. Mosso and Waller have shown that intellectual work induces muscular fatigue. (J.M.B.)

Literature: The recognition of a distinct muscle sense appears to go back to ARISTOTLE (Hist. An., i. 4; De Part. An., ii. 1, 10; De Anima, ii. 11). It certainly goes back to SCALIGER (De Subtil., 1557). Cf. HAMILTON, ed. of Reid (1880), 867. The modern doctrine of the muscle sense may be said to begin with Sir CH. BELL. An excellent résumé to 1898 is by HENRI (Année Psychol., v. 1899), who (cf. also JOTEYKO, ibid., on muscular fatigue) traces the subject back to Descartes. Henri gives a bibliography of 391 titles. KÜLPE, Outlines of Psychol., 143; GOLDSCHEIDER, Du Bois-Reymond's Arch. (1889), 369, 540, and Suppl. -Bd.; BASTIAN, Brain as Organ of Mind, 691; SANFORD, Course in Exper. Psychol. expt. 26; FULLERTON and CATTELL, Perc. of Small Differences (1892); BEAUNIS, Les Sensations internes; E. GLEY, Rev. Philos. (Dec., 1889); L. MOULDER, Expériences sur le Sens musculaire, Rev. Philos. (April, 1887); MORSELLI, Semej. malat. ment., ii (1895); E. CLAPARÈDE, Du Sens musculaire. See also the citations under FATIGUE (mental). (E.B.T.- L.M.- J.M.B.)

Music [Gr. mousikh]: Ger. Musik; Fr. musique; Ital. musica. The fine art which employs tones produced in rhythmic succession.

Making rhythm the essential to music, complex effects are produced by added factors, notably melody, in which the succession is marked by recurring similarities, and HARMONY (q.v.), in which complex simultaneous tone effects are employed.

The problems connected with music are principally the following. (1) The essential factor or factors. (2) The enhancing of the musical effect by the additional factors: how and why harmony, for example, is combined with melody in a musical whole. (3) The origin of music and its development as a fine art. (4) The relation of music to the other arts in general aesthetic theory (cf. ART AND ART THEORIES, and CLASSIFICATION of the fine arts). (5) The nature of musical enjoyment; its emotional and other psychological elements.

The origin of music has been found by some in association with the early dance, the latter being held to have supplied the element of rhythm to which rude instruments beat the accompaniment. Others connect music with spontaneous cries, particularly those of the mating season. The song of birds is the best illustration of the employment of successive notes for the purposes of instinctive expression.

As to the 'meaning' or 'expression' conveyed by music, the two current views are widely apart. Some hold -- and possibly the best psychological opinion is with this view -- that the musical effect is purely a sensuous one; when, however, the sensuous ingredients of higher emotional and sentimental states are aroused through this connection, the music itself is considered to express or 'mean' the emotion or sentiment. General moods and dispositions are, no doubt, ministered to by music, through differences of rhythm, &c., and so come to be expressive to the hearer, of what he already finds in himself. The other theory -- held principally by musicians, who are certainly entitled to an opinion -- maintains that music is expressive of emotions and thoughts; indeed, that a musical composition is analogous to a drama in the unfolding and presentation of a theme or narrative. The views of musicians, however, are generally mystical and obscure.

Literature: SPENCER, Princ. of Sociol.; WALLASCHEK, The Origin of Music; HIRN, The Origins of Art; works on HARMONY (q.v.). Also HELMHOLTZ, Sensations of Tone (Eng. trans.); GROVE, Dict. of Music; GURNEY, The Power of Sound; the literature of Wagner and Wagnerism. (J.M.B.)

Musical Tone: Ger. Ton, Klang; Fr. son; Ital. suono (or tono) musicale. See TONE (and CLANG), and COMPOUND TONE.

Mutation (in biology) [Lat. mutare, to change]: Ger. Mutation; Fr. mutation; Ital. mutazione. A term introduced by W. Waagen to denote the hypothesis that the causes of modification lie deep in the specific nature and affect uniformly large numbers of individuals simultaneously. Cf. VARIATION.

The essence of this idea, like many other rechristened at a later date, passed through the mind of Darwin, was weighed and found wanting. Thus, long before nature selection had presented itself to him, he wrote of the causes of extermination acting from within the specific nature and leading to the simultaneous dying-out of the whole of the individuals of a species spread over, perhaps, a vast tract of country. He also thought of such species as compelled by their constitution to change into other species or else to die out. W. B. Scott has argued that the evidence of paleontology is consistent with 'that steady advance along certain definite lines which Waagen called mutation,' while he considers it inconsistent alike with (1) the 'discontinuous evolution' of W. Bateson, or 'transilience' of F. Galton, depending on the occurrence of large variations, and with (2) the accumulation of minute individual differences by natural selection. The former criticism is undoubtedly well aimed. Bateson's statement is an account of what he believes has happened rather than a theory of causes. Paleontology is an account of what has happened; and whenever it yields a complete account, the history is continuous and not discontinuous. On the other hand, the record of paleontology is exactly what the natural-selectionist would expect. W. B. Scott indeed says, 'The direct, unswerving way in which development proceeds, however slowly, is not suggestive of many trials, and failures in all directions save one.' The contemplation of a series of pigeons' skeletons, from the most modern product of artificial selection right back to the ancestral rock dove, would lead this distinguished paleontologist to similar conclusions, did he not in this case know the history and the creative part selection has played. The phenomena mutation has been invoked to explain are precisely the phenomena we should expect to appear if evolution has been the product of the action of natural selection upon minute individual differences. The upshot of the struggle for existence as we see it waged to-day, with its 'many trials' and 'failures in all directions save one,' the one which leads to the survival of a minute fraction of each generation, could, with our present knowledge, but rarely be inferred from a study of the skeletons of the individuals concerned. How much less should we be justified in expecting to reconstruct the details of its operation by a careful study of the skeleton of forms, of which in the living state nothing directly is known? But while we cannot expect, as yet, to recover these details, the general trend of evolution is exactly what the selectionist would anticipate, exactly what is unexplained by any other theory than natural selection; viz. an advance along a line of ever more perfect adaptation to their past environments, so far as their main features can be reconstructed. (E.B.P.)

The theory of mutation seems to have received some support from a research of de Vries published since the above paragraphs were written, although it is too early to judge as to its permanent value. The following passage is quoted from an article signed J. P. K. in Nature, June 27, 1901: --

'De Vries has just published the first part of a book entitled "Die Mutationstheorie. Erster Band. Versuche und Beobachtungen über die Entstehung von Arten im Pflanzenreich" (Leipzig: Veit, 1901), containing, as the title indicates, the account of a series of observations on the formation of a new species in plants. Starting from the fact, well known to florists, of the appearance of "single variations" in their flower-beds, de Vries has been trying to find wild flowers which would show the same phenomenon. Of the 100 species investigated only one appeared to possess the property which was looked for, the Oenothera Lamarckiana, originally from America, but at present growing wild in Holland. Now about ten years ago de Vries transferred specimens of this plant to the botanical gardens at Amsterdam, and up to date he has studied as many as 50,000 of its descendants.

'Of these 50,000 about 49,200 were in no respect different from the original patriarchal O. Lamarckiana, showing no tendency towards gradual change in any special direction, but only the common small fluctuating "variations" as regards size and appearance on either side of a normal, in fact resembling in that respect other plants and animals which are left to themselves without being interfered with.

'Quite otherwise the 800 other plants. None of these, although appearing spontaneously, could be said to be representatives of the species Lamarckiana, from which they were descended. De Vries arranges them in seven distinct species, viz. 1 of O. gigas, 56 of O. albida, 350 of O. oblonga, 32 of O. rubrinervis, 158 of O. nanella, 221 of O. lata, and 8 of O. scintillans. Now comes the crucial question of the whole investigation What right has de Vries to look upon the differences between these seven species and the original species as being of a different order from the variations between the specimens of each species, and what entitles him to call these differences mutations as opposed t variations? The answer in this: a representative of these new species produces descendants the majority of which unmistakably belong to the same species as itself. Not all the new species behave in the same way; as an instance, the only representative of O. gigas was isolated and made to fertilize itself. From it were obtained 450 plants, all of which, with only one exception, were O. gigas, the one exception not being a return to Lamarckiana but belonging to a new variety. The plant is a strong one and retains its properties in subsequent generations so far as investigated.

'The O. albida, on the other hand, which appeared frequently, is a weak plant, not very fertile, but perfectly constant so far as it went. The last species in the above list, the O. scintillans, differs from the others in this respect, that it is extremely unstable, i.e. possesses the property of mutation to a high degree, a large proportion of its descendants belonging to other species, specially O. oblonga and Lamarckiana itself.

'Enough has been said to show that de Vries has evidently made a momentous discovery. So far as his observations go, new species appear suddenly by mutation, never as the outcome of a progressive variation. . . . .As we saw, some of the new species which made their appearance did not seem to be inferior in stability to the mother-species; on the other hand, one of the species, the O. lata, only appeared as female plants without pollen, and the O. albida did not show the same, vitality as the others and was evidently doomed to disappear again: The observations, therefore, do not support the idea that in the formation of new species Nature is carrying out a definite plan; on the contrary, it all looks like accident. A new species may be one strong and fertile enough to remain, and possibly, under favourable conditions, replace the mother-species, but it may just as well be sickly kind without any chance in the struggle for existence. For the struggle for life between individuals de Vries substitutes the struggle for continued existence between species, the new species always appearing suddenly.

'De Vries' views are thus directly opposed to the common form of the theory of evolution; not that the importance of the single variations had escaped attention altogether, but they were always lost sight of, and prime importance is generally attached to the selection through the ordinary variations. De Vries' experiments support the results arrived at by Scott and other paleontologists that there is no evidence in the successive strata of the earth of a gradual development of one species into another and that everything points at small but sudden transitions.' (J.M.B.)

Literature: W. WAAGEN, Die Formenreiche des Ammonites subradiatus, in Benecke's Geognost. Palaeontol. Beitr., ii. 179-256; W. B. SCOTT, On Variations and Mutation, in Amer. J. of Sci. (1894), x1viii. 355; W. BATESON, Materials of the Study of Variation (London, 1894); Life and Letters of Charles Darwin (London. 1887); CONN, The Method of Evolution; BAILEY, and DE VRIES (as cited above). (E.B.P.- J.M.B.)

Mutism [Lat. mutus, dumb]: Ger. Mutismus; Fr. mutisme; Ital. mutismo. The lack of development or the functional inhibition of the faculty of speech. It is contrasted with aphasia, which is defect or organic disturbance of speech. Cf. SPEECH AND ITS DEFECTS. (J.M.B.)

The most frequent form of mutism, which may be partial or complete, is that arising from congenital or early deafness. See DEAF-MUTISM. Mutism may also be the result of serious mental defect or disorder (idiocy), of mental stupor, of a delusional insanity in which the patient for some insane reason refuses to speak. Hysterical mutism, like hysterical aphonia, is of that special type peculiar to hysterical disturbances. See HYSTERIA. Mutism of an allied nature is also symptomatic of the disease KATATONIA (q.v.). (J.J.)

Mutuality [Lat. mutuus, from mutare, to change]: Ger. Gegenseitigkeit; Fr. mutualité, échange mutuel; Ital. mutuazione. Double relation of give and take, in which the two relations are identical. (J.M.B.)

Myelitis (chiefly in combination) [Gr. mueloV, marrow]: Ger. Rückenmarksentzündung, Myelitis; Fr. myélite; Ital. mielite. A diseased condition of the spinal cord.

Leucomyelitis is a diseased condition of the white or fibrous matter of the cord. Primary lesions of the white column consist in destruction of the nerve fibres and simultaneous increase of the neuroglia. The medullary sheaths are the first to be affected. Granular corpuscles collect in the lymph-spaces about the blood-vessels. The so-called crossed pyramidal tracts are most frequently affected with sclerosis. Secondary degenerations in the cord also result from injuries to the motor areas of the cortex and the basal centres. Cf. DEGENERATION. Poliomyelitis, or degenerative atrophy of the anterior cornea, occurs as 'infantile paralysis' and 'chronic anterior poliomyelitis' in adults. The last named is very obscure. (H.H.)

Myo- (in compounds) [Gr. muV, muscle]: the same in other languages. Muscle (in compounds or expressions); as myograph, an instrument for recording the contraction of a muscle. (J.M.B.)

Myograph: see MYO-, and LABORATORY AND APPARATUS, III, A.

Myopia [Gr. muein, to close, + wy, the eye]: Ger. Kurzsichtigkeit; Fr. myopie; Ital. miopia. Near-sightedness; short-sightedness, hypometropia, brachymetropia; the condition of an eye in which, with relaxed accommodation, parallel rays of light are brought to a focus before they reach the retina.

Its most frequent cause is an abnormal elongation of the antero-posterior axis of the eye-ball, and it may then be termed axial; it may also be due to excessive convexity of the refracting media (myopia of curvature) or to an excessive index of amount of refraction of the dioptric constants (index myopia). In myopia the rays of light are dispersed on the retina, and the confused images which thus result must be corrected by the use of concave lenses of suitable strength. The statistics and causes of myopia furnish an important topic in discussion of the hygiene of vision in the school-room and elsewhere. The opposite of myopia is HYPERMETROPIA (q.v.); both are forms of Ametropia as opposed to Emmetropia. See also VISION (defects of), and PRESBYOPIA.

Literature: J. S. WELLS, Dis. of the Eye (Amer. ed., 1883), 629; NORRIS and OLIVER, Syst. Dis. of the Eye. (J.J.)

Mysteries [Gr. musthrion, secret doctrine or rite]: Ger. Mysterien; Fr. mystères; Ital. misteri. Those rites of the ancient Greek religions which were concealed from the view of the public and practised only by persons who had been solemnly initiated and set apart for that service.

In Christian theology, hidden truths that have been brought to light through divine revelation; or the Sacraments of the Church, particularly the Eucharist. (A.T.O.)

Mysticism [Gr. mustikoV, belonging to secret rites]: Ger. Mystik, Mysticismus; Fr. mystique, mysticisme; Ital. misticismo. Those forms of speculative and religious thought which profess to attain an immediate apprehension of the divine essence or the ultimate ground of existence.

Mysticism springs most frequently from the religious desire to an intimate communion with God, when this is allied with a temperament of speculative boldness. But whereas ordinary religion realizes such communion in the life of ethical endeavour and aspiration, the practical element in religion is overmastered in the mystic by the metaphysical. Penetrated by the thought of the ultimate unity of all existence, and impatient of even a seeming separation from the creative source of things, mysticism, succumbs to a species of metaphysical fascination. Its ideal becomes that of passive contemplation, in which the distinctions of individuality disappear, and the finite spirit achieves, as it were, utter union or identity with the Being of beings. As this goal cannot be reached under the conditions of relation and distinction which ordinary human thought imposes, mysticism asserts the existence of a supra-rational experience in which this union is realized. Such is the intuition or ecstasy or mystical swoon of the Eastern mystics, the mystical or metaphysical love (erwV) of the Neo-Platonists, and 'gifts' of the mediaeval saints. Bonaventura speaks of the 'apex mentis' or 'scintilla,' and Meister Eckhart of the 'Fünklein' or spark, as the faculty by which the mystical union is attained. In a more purely speculative form, a similar appeal to a 'higher' faculty or mode of apprehension is made by Schelling in his theory of intellectual intuition; and Schopenhauer describes in similar terms the vision of the Platonic ideas in which he conceives the mind to achieve its emancipation from the evils of finitude and the sway of the irrational will. In both these cases, however, the inspiration is drawn from the aesthetic rather than the religious sphere.

The element of truth in mysticism is its keen realization of the metaphysical unity of existence, and, in particular, of the intimacy of the relation between the finite spirit and the infinite. Intense religious feeling tends to be tinged with mysticism; and historically, both in philosophy and in religion, mysticism frequently appears as a protest against mechanical, external, or anthropomorphic fashions of representing the divine and its relations to man and the world. But in its impatience of separation it overleaps the conditions of thought altogether, and in its reaction against anthropomorphism it neglects the element of relativity which must enter into all human conceptions of the absolute. A union so immediate that the distinction of subject and object disappears involves the suppression or absorption of the conscious person; the mystics themselves describe 'the ecstasy' in terms which leave it indistinguishable from a lapse into unconsciousness. Mysticism becomes, in fact, the victim of sensuous metaphor applied to supersensuous or spiritual experience, and treats the relation of ethical harmony and dependence between the divine and the human spirit as if it were one of chemical fusion or interpenetration of substances. Moreover, in its attempt to transcend the bounds of reason and to exalt the divine above all anthropomorphic predicates, mysticism leaves us, as in Neo-Platonism, with the empty abstraction of the nameless and supra-essential One -- the One which transcends both knowledge and existence (epekeina ihV ousiaV). We reach a truer and more adequate account of the absolute when, with a justifiable and inevitable anthropomorphism, we interpret its nature according to the highest categories of our own experience. As Cousin has well said: 'The true union of the soul with God takes place through virtue and truth. Every other union is a chimera, a peril, sometimes a crime. It is not permitted to man to abdicate under any pretext what makes him man and renders him capable of understanding God and expressing in himself an imperfect image of him, that is to say, reason, will, consciousness.'

Mysticism is sometimes used, by writers of an empirical or positivistic bias, as a dyslogistic term or opprobrious epithet, and is apparently extended to cover any system of so-called 'transcendental' philosophy, which accepts other data than sensation and association. So it appears to be used by Mill (Logic, Bk. V. chap. iii. § 4), where he introduces it under the head of 'a priori fallacy or natural prejudice.' In a somewhat similar sense, but with an intention to commend, it is applied by a writer like Carlyle to any philosophy which does not limit itself to the world of 'the visible' and 'our logical mensurative faculty' (cf. the Essay on the State of German Literature, and Sartor Resartus; iii. 3). Such a usage is, however, quite inexact.

In defining mysticism some reference has already been made to its historical appearances. In India the Brahmanic pantheism has always lent itself to a mystical ascetiscism. In Western thought mysticism appeared in the Orphic-Pythagorean sects (cf. Rohde, Psyche). The theosophical speculation of Plotinus and other Neo-Platonists -- foreshadowed in the so-called Neo-Pythagoreans, and, to some extent, in the contemplative asceticism of the Essenes and in Philo Judaeus -- culminates in the idea of mystical union with the utterly transcendent One. Ecstasy, coalescence, contact (ekstasiV, aplwsiV, afh) are some of the terms used by Plotinus to describe this union (Enneads, vi. 9. 8-9). The speculative mysticism of Neo-Platonism was transfused into Christian thought through the literary forgeries of the Pseudo-Dionysius. Dionysius was translated into Latin by Scotus Erigena who adopts his 'negative theology' and the idea of God as exalted above all predicates, and therefore, 'on account of his pre-eminence, not improperly called Nothing.' Religious mysticism first appears in the mediaeval Church in Bernard of Clairvaux, as a protest against the dialectical spirit of Abelard. It was cultivated by the Victorines and also by various heretical sects. The greatest of the mediaeval mystics was Meister Eckhart, among whose followers are reckoned Heinrich Suso, Johann Tauler, and the anonymous author of the Deutsche Theologie. The mysticism of Ruysbroeck in the Netherlands was less speculative in character. Nicolaus of Cusa teaches a species of intellectual intuition which he describes as 'comprehensio incomprehensibilis.' Boehme's system of theosophy is one of the chief monuments of mystical thought. In the field of modern philosophy, mysticism is represented in the 17th century by the Cambridge Platonists, especially Henry More. Some of the phases of Schelling's thought are strongly tinged with mysticism; and thinkers like Novalis, Carlyle, and Emerson, whose philosophical tenets are reached by vivid insight rather than by 'the labour of the notion,' often exhibit a mystical tendency. Swedenborg, on the other hand, though treated by Emerson in his Representative Men as the typical mystic, has few of the traits of speculative and religious mysticism, strictly understood. (A.S.P.P.)

The word is used also in recent discussion for the pursuit of the occult, in psychical appearances, spiritualism, and the various forms of magic. The spread of irreligious views, i.e. the decline of the recognition of the supernatural, properly characterized as religious, induces various mystical substitutes for it. Höffding (Hist. of Mod. Philos., Eng. trans., ii. 328 ff.) cites the mysticism of Comte; Guyau (Non-religion of the Future) dwells upon the 'recrudescence of faith'; Renan sublimates religion in a form of poetic mysticism; the rise of various 'isms' and 'ologies,' such as 'Christian Science,' 'metaphysical healing,' &c., especially in 'free-thought' communities, bears witness to the vitality of a broadly-defined mystic consciousness (cf. Münsterberg, Psychol. and Life, 'Mysticism'). (J.M.B.)

Literature: besides the numerous accounts of NEO-PLATONISM (q.v.), reference may be made to NOACK, Die christl. Mystik des Mittelalters; PREYER, Gesch. d. deutschen Mystik; COUSIN, Hist. de la Philos. moderne, tom. ii, leçon 9. Also RÉCÉJAC, Basis of the Mystic Knowledge (Eng. trans., 1899); TROILO, Il Misticismo moderno (1899); DELACROIX, Mysticisme spéculatif en Allemagne (1900); ORMOND, Foundations of Knowledge, Pt. III. chap. ix. (A.S.P.P.- E.M.)

Myth [Gr. muqoV, word, legend]: Ger. Mythe; Fr. mythe; Ital. mito. A story, the spontaneous product of a primitive unreflecting and uncritical consciousness, in which the forces of nature or other agents are represented in personal or quasi-personal forms, and as performing supernatural or super-human actions.

A myth is to be distinguished from a legend whose subject is, as a rule, some human being rather than a force of nature. It differs from a fable or parable in being direct and spontaneous, having in it no element of reflection or external design. In an abusive sense the term has become a synonym for pure fiction, although the author of a myth is not conscious of producing a fictitious representation.

Literature: see MYTHOLOGY. (A.T.O.)

Mythical Theory: Ger. Mythentheorie; Fr. théorie mythique; Ital. teoria mitologica. The special designation of the method of Strauss and his followers in explaining the supernatural elements in the story of Jesus as myths or products of the mytho-poetic faculty.

Strauss, in his Leben Jesu, starts by recognizing the fact of the human life of Jesus. The supernatural elements arose, he maintains, out of the expectation among the Jews that their Messiah would perform miracles and supernatural actions. Out of this the supernatural elements spontaneously originated in the imagination of the disciples. Strauss maintains that while these myths are fictitious as elements of the historic life of Jesus, they nevertheless represent abstract truths regarding humanity as a whole.

Literature: D. STRAUSS, Leben Jesu (1833); P. SCHAFF, The Person of Christ (1883); G. P. FISHER, Essays on the Supernatural Origin of Christianity (1866). (A.T.O.)

Mythology [Gr. muqologia]: Ger. Mythologie; Fr. mythologie; Ital. mitologia. Either the body of myths which embody the primitive religious conceptions of a people or race, or the investigation of mythic materials, in order to reduce them to scientific form.

The first reflective treatment of the myth arose among the early Greek thinkers as an effort to develop from it a more rational explanation of the world. This attempt was the parent of both science and philosophy. It was only in modern times and in the present century that the science of mythology originated in a comparative study of the myths of all nations. The most important recent controversy that has developed in this field is that between the philologists led by Max Müller and certain anthropologists whose champion is Andrew Lang, on the issue raised by Max Müller's claim that mythology is a disease of language.

Literature: TYLOR, Primitive Culture; MAX MÜLLER, Oxford Essays (1856); ANDREW LANG, art. Mythology, in Encyc. Brit. (9th ed.); Custom and Myth; and Myth and Ritual and Religion; H. SPENCER, Princ. of Sociol.; SAUSSURE, Lehrb. d. Religionsgesch. (Freiburg, 1887-9); VIGNOLI, Myth and Science (Eng. trans., 1882).