that localizing an impression consists wholly and solely in performing or imaging the particular movements necessary to add active touches to a group of passive impressions. That this cannot sufhce is evident merely from the consideration that a single position out of relation to all other positions is a contradiction. Localization, though it depends on many special experiences of the kind described, is not like an artificial product which is completed a part at a time, but is essentially a growth, its several constituents advancing together in definiteness and inter connexion. So far has this development advanced that we do not even imagine the special movements which the localization of an impression implies, that is to say, they are no longer distinctly represented as they would be if we definitely intended to make them: the past experiences are “ retained, ” but too much blended in the mere perception to be appropriately spoken of as remembered or imaged.
A propos of this almost instinctive character of even our earliest spatial percepts it will be appropriate to animadvert on a misleading implication in the current use of such terms as “ localization, ” “ projection, " “ bodily reference, " “ spatial reference ” and the like. The implication is that external space, or the body as extended, is in some sort presented or supposed apart from the localization, projection or reference of impressions to such space. That it may be possible to put a book in its place on a shelf there must be (I) the book, and (2), distinct and apart from it, the place on the shelf. But in the evolution of our spatial experience impressions and positions are not thus presented apart. /Ve can have, or at least we can suppose, an impression which is recognized without being localized as has been already said; but if it is localized this means that a more complex presentation is formed by the addition of new elements, not that a second distinct object is presented and some indescribable connexion established between the impression and it, still less that the impression is referred to something not strictly presented at all. The truth is that the body as extended is from the psychological point of view not perceived at all apart from localized impressions. In like manner impressions projected (or the absence of impressions projected) constitute all that is perceived as the occupied (or unoccupied) space beyond. It is not till a much later stage, after many varying experiences of different impressions similarly localized or projected, that even the mere materials are present for the formation of such an abstract concept of space as “spatial reference" implies.1 Psychologists, being themselves at this later stage, are apt to commit the oversight of introducing it into the earlier stage which they have to expound. zo. In a complex percept, such as that of an orange or a piece of wax, may be distinguished the following points concerning which psychology may be expected to give an
Intuition of h b., 1. b . 1. .
2-, ,, ,, g, account. (zz) t eo ject srea ity, () 1tSSO.1d1ty or occupation of space, (6) its unity and complexity, (d) its permanence, or rather its continuity in time and (e) its substantiality and the Connexion of its attributes and powers. Though, in fact, these items are most intimately blended, our exposition will be clearer if we consider each for a moment apart. a. The terms actuality and reality have each more than one meaning. Thus what is real, in the sense of material, is opposed to what is mental; as the existent or actual it is "°'"°""'°' <1 11 ' - <1 ' ht' 1
Ream” oppose tot e non-existent, an aga1n, w a 1S actua is distinguished from what is possible or necessary. But here both terms, with a certain shade of difference, in so far as actual is more appropriate to movements and events, are used, in antithesis to whatever is ideal or represented, for what is sense-given or presented. This seems at least their primary psychological meaning; and it is the one most in vogue in English philosophy at any rate, over-tinged as that is with psychology.” Any examination of this characteristic will be best deferred till we come to deal with ideation generally (see § 21 below). Meanwhile it may suiiice to remark that reality or actuality is not a single distinct element added to the others which enter into the complex presentation we call a thing, 1 Cf. on this point Poincaré, La Science et Vhypothése, pp. 74 sqq. 2 Thus Locke says, “Our simple ideas [i.e. presentations or impressions, as we should now say] are all real. .and not fictions at pleasure; for the mind .can make to itself no simple idea more than what it has received " (Essay, ii. 30, 2). And Berkeley says, “The ideas imprinted on the senses by the Author of Nature are called real things; and those excited in the imagination, being less regular, vivid and constant, are more properly termed ideas or images of tfzirggs, fvhich they copy or represent" (Pun, of Hum. Know., pt. 1. 33 .
as colour or solidity may be. Neither is it a special relation among these elements, like that of substance and attribute, for example. In these respects the real and the ideal, the actual and the possible, are alike; all the elements or qualities within the complex, and all the relations of those elements to each other, are the same in the rose represented as in the presented rose. The difference turns not upon what these elements are, regarded as qualities or relations presented or represented, but upon whatever it is that distinguishes the presentation from the representation of any given qualities or relations. Now this distinction, as we shall see, depends partly upon the relation of such complex presentation to other presentations in consciousness with it, partly upon its relation as a presentation to the subject whose presentation it is. In this respect we find a difference, not only between the simple qualities, such as cold, hard, red and sweet in strawberry ice, e.g. as presented and as represented, but also, though less conspicuously, in the spatial, and even the temporal, relations which enter into our intuition as distinct from our imagination of it. So then, reality or actuality is not strictly an item by itself, but a characteristic of all the items that follow.
b. In the so-called physical solidity or impenetrability Of things our properly motor presentations or “feelings of eliort
or innervation come specially into play. They Impenetrp are not entirely absent in those movements of b, ”ty exploration by which we attain a knowledge of space; but it is when these movements are definitely resisted, or are only possible by increased effort, that we reach the full meaning of body as that which occupies space. Heat and cold, light and sound, the natural man regards as real, and by and by perhaps as due to the powers of things known or unknown, but not as themselves things. At the outset things are all corporeal like his own body, the first and archetypal thing, that is to say: things are intuited only when touch is accompanied by pressure; and, though at a later stage passive touch without pressure may suffice, this is only because pressures depending on a subjective initiative, 13.6. on voluntary muscular exertion, have been previously experienced. It is of more than psychological interest to remark how the primordial factor in materiality is thus due to the projection of a subjectively determined reaction to that action of a not-self of which sense-impressions consist-an action of the not-self which, of course, is not known as such till this projection of the subjective reaction has taken place. Still we must remember that accompanying sense-impressions are a condition of its projection: muscular effort without simultaneous sensations of contact would not yield the distinct presentation of something resistant occupying the space into which we have moved and would move again. Nay more, it is in the highest degree an essential circumstance in this experience that muscular effort, though subjectively initiated, is still only possible when there is contact with something that, as it seems, is making an efiort the counterpart of our own. But this something is so far no more than thing-stuff; without the elements next to be considered our psychological individual would fall short of the complete intuition of distinct things.
e. The remaining important factors in the psychological constitution of things might be described in general terms as the time-relations of their components. Such rela—Unity and
tions are themselves in no way psychologically deter-Complexim mined; impressions recur with a certain order or want of order quite independently of the subject's interest or of any psychological principles of synthesis or association whatever. It is essential that impressions should recur, and recur as they have previously occurred, if knowledge is ever to begin; out of a continual chaos of sensation, all matter and no form, such as some philosophers describe, nothing but chaos could result. But; a fiux of impressions having this real or sense-given order will not suffice; there must be also attention to and retention of the order, and these indispensable processes at least are psychological.
But for its familiarity we should marvel at the fact that out of the variety of impressions simultaneously presented we do