say, experimentally-first by anaesthesia or paralysis, which may suspend some of them, and secondly by movements of our limbs or body, so-called 'passive movements,' effected externally. Unlike many organic sensations, of which we are scarcely conscious save when the organs are out of gear, these motor presentations pertain exclusively to the normal working of such organs as we directly control. These have their own strictly 'organic sensations' as in fatigue from excessive exercise, or its opposite, that want of exercise which might be called 'muscular hunger.' In describing such complexes as motor presentations, we need carefully to guard against importing spatial implications into the term. As 'sensed' but not perceived, they have extensity and protensity, but imply neither time nor space nor motion. But as normally experienced they have always one characteristic of physical movement that does not belong to the mere geometry of motion: though they do not directly and alone. suffice to make us acquainted with position or direction or velocity, certain of them do make us acquainted with 'force' both as freely exerted and as more or less completely resisted. In other words, though none of them as such are kinematic, there is one constituent always present in 'active movement' that is kinetic, or dynamic, using this term, as physicists do, to cover both momentum and pressure. It may be thought that in 'free' unimpeded movements there is no sense of effort. But that some effort is present, however unobtrusive, may be inferred from the fact that even such movements, if continued long enough, lead to fatigue. But the experience of force would be of no practical avail without the other constituents which help to prepare the way for spatial perception. It seems well therefore to confine the useful term 'kinaesthetic sensations,' which was proposed as a name for the whole group', to its last-mentioned constituents exclusively. They might be more significantly called 'dirigo-motor' if Spencer had not unfortunately misapplied this term to the kinetic factor itself. I have suggested 'auxiliomotor'; but, so far as I know, it has not been adopted. It is because of the absence of these sensations that the anaesthetic 1 Bastian, The Brain as an organ of Mind, 1880, p. 543. The term is useful as avoiding the confusion of psychology and physiology which the term 'muscular sense' involves. patient cannot directly tell whether his efforts have been effectual or not, nor in what position his limbs have been placed by movements from without, but has to fall back on the indirect evidence afforded him by sight'. Movements, we must suppose, originally belonged to one undifferentiated, or rather imperfectly differentiated continuum; but, as development advanced, tended more and more to become like sensations, a collection of special continua, i.e. groups of distinct movements separately possible and admitting of definite combinations in various ways. Whereas kinaesthetic presentations were commonly allowed to be purely sensory-the concomitants of various centripetal excitations from skin, tendons, muscles, &c.-a very different view long prevailed concerning motor presentations proper, a view, however, now generally discredited, if not completely overthrown1. According to this view, "the characteristic feeling of exerted force" must be regarded, Bain maintained, "not as arising from an inward transmission...but as the concomitant of the outgoing current by which the muscles are stimulated to act" (Op. cit. p. 79). The necessity for this assumption has certainly not been established on physiological grounds, nor apparently did Bain rely primarily on these; for at the very outset of his discussion we find him saying "that action is a more intimate and inseparable property of our constitution than any of our sensations, and enters as a component part into every one of our senses" (Op. cit. p. 59). But this important psychological truth is affirmed as strenuously by some, at any rate of Bain's opponents (e.g. William James) as it was by Bain himself. Unhappily many, under the same psychophysical bias and so induced, like the upholders of this innervation theory, to look for evidence of subjective activity in the wrong place, have been led to doubt or to deny the reality of this activity altogether. 1 The stock instance is that of an unfortunate woman who was liable to drop her baby if she took her eyes off it. 2 Hence the older name of 'muscular or sixth sense' applied to them by Sir Charles Bell, Weber, Sir William Hamilton and others. 3 First tentatively advanced by the great physiologist Johannes Müller, and adopted by Helmholtz, Ludwig, Wundt, and especially by Bain. 4 Cf. Bastian, Op. cit. pp. 691 sqq.; Ferrier, The Functions of the Brain (1886), 2nd ed., pp. 382 sqq.; James, Principles of Psychology (1890), ch. xxvi. 5 Precisely for this reason activity is not to be regarded as presentational at all. Cf. above, ch. iii, § 2. In fact, this theory, while it lasted, tended to sustain an undue separation of so-called 'sensory' from so-called 'motor' presentations, as if living experience were literally an alternation of two independent states, one wholly passive and the other wholly active, corresponding to the anatomical distinction of organs of sense and organs of movement. The subject of experience or Ego does not pass to and fro between a sensorium commune or intelligence department and a motorium commune or executive, is not in successive intervals merely receptive or merely active, still less always passive; but is rather always actively en rapport with an active Non-Ego, commonly called the External World. CHAPTER VI PERCEPTION Integration: Meanings of Perception. §1. IN treating apart of the differentiation of our sensory and motor continua, as resulting merely in a number of distinguishable sensations and movements, we have been compelled by the exigencies of exposition to leave out of sight another process which really advances pari passu with this differentiation, viz. the integration or synthesis of these proximately elementary presentations into those complex presentations which are called percepts, intuitions, sensori-motor reactions and the like. It is, of course, not to be supposed that in the evolution of mind any creature attained to such variety of distinct sensations and movements, as a human being possesses, without making even the first step towards building up this material into the most rudimentary knowledge and action. On the contrary, there is every reason to think, as has been said already incidentally, that further differentiation was helped by previous integration, that perception prepared the way for distincter sensations, and purposive action for more varied movements'. This process of synthesis, which is in the truest sense a psychical process, deserves some general consideration before we proceed to the several complexes that result from it. Certainly the most important—if not all—of these complexes are consequences of that principle of subjective selection whereby interesting sensations lead through the intervention of feeling to movements; and whereby the movements that turn out to subserve such interest come to have a share in it. In this way-which we need not stay to examine more closely now— it happens that a certain sensation, comparatively intense, and 1 Cf. ch. iv, § 3, p. 81. a certain movement, definite enough to control that sensation, engage attention, to the more or less complete exclusion of the other less intense sensations and more diffused movements that accompany them. Apart from this intervention of controlling movements, the presentation-continuum—no matter how much it became differentiated-would still remain, for all purposes of knowledge, little better than the disconnected manifold for which Kant took it. At the same time it is to be remembered that the subject obtains command of particular movements out of the general mass involved in emotional expression only because such movements, when they occur, are found to control certain sensations. Before experience, and apart from heredity, there seems not only no scientific warrant for assuming any sort of practical prescience but also none for the hypothesis of a priori forms of knowledge. Nor is there any evidence of a preestablished harmony between the active and affective states of the subject, or-it may be safer to say-there is indefinitely little painful reactions are aversive and pleasurable reactions become appetitive. A sentient creature moves first of all, as we have already seen, because it feels, not because it intends. A long process of trial and error must have been necessary to secure as much purposive movement as even a worm displays. In this process natural selection probably played the chief part at the outset, subjective selection becoming more prominent as the process advanced. It seems impossible to except from this process the movements of the special sense-organs. Here too subjective interest will explain, so far as psychological explanation is possible, those syntheses of motor and sensory presentations which we shall call spatial percepts and intuitions of material things. For example, some of the earliest lessons of this kind. seem to be acquired, as we may presently see, in the process of exploring the body by means of the limbs,—a process for which grounds in subjective interest can obviously never be wanting. All such syntheses or integrations depend primarily on what we have called 'movements of attention' (cf. ch. iii, § 3), which movements in turn depend very largely upon the pleasure or pain that presentations occasion. To some extent, however, there is no doubt that attention may pass non-voluntarily from one indifferent presentation to another, each being sufficiently intense to give what has been called a 'shock of surprise,' but |