PSYCHOLOGY the body probably our earliest lesson in spatial perception these auxilio-motor presentations receive a new signifi- cance from the active and passive touches that accompany them, just as they impart to these last a significance they could never have alone. It is only in the resulting complex that we have the presentations of position and of spatial magnitude. For space, though conceived as a coexistent continuum, excludes the notion of omnipresence or ubiquity ; two positions ) ' d and l g must coexist, but they are not strictly distinct positions so long as we conceive ourselves present in the same sense in both. But, if F d and F g are, e.g., two impressions produced by compass -points touching two different spots as I and l g on the hand or arm, and we place a finger upon l d and move it to l y , experiencing thereby the series P^P^P^P^ this series constitutes l d and l g into positions and also invests F d and F g with a relation not of mere distinctness but of definite distance. The resulting complex perhaps admits of symbolization as follows : T t t t Here the first line represents a portion of the tactual continuum, F d and F g being distinct " feels," if we may so say, or passive touches presented along with the fainter sensations of the continuum as a whole ; T stands for the active touch of the exploring finger and P l for the corre- sponding auxilio-motor object ; the rest of the succession, as not actually present at this stage but capable of re- vival from past explorations, is symbolized by the ttt and PiPsPv When the series of movements is accompanied by active touches without passive there arises the distinc- tion between one's own body and foreign bodies ; when the initial movement of a series is accompanied by both active and passive touches, the final movement by active touches only, and the intermediate movements are unaccompanied by either, we get the further presentation of empty space lying between us and them, but only when by frequent experience of contacts along with those intermediate move- ments we have come to know all movement as not only succession but change of position. Thus active touches come at length to be projected, passive touches alone being localized in the stricter sense. But in actual fact, of course, the localization of one impression is not perfected before that of another is begun, and we must take care lest our necessarily meagre exposition give rise to the mistaken notion 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 im- pressions. That this cannot suffice 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 de- scribed, is not like an artificial product which is completed a part at a time, but is essentially a growth, its several constituent^ocalizations advancing together in definiteness and interconnexion. 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. Apropos of this almost instinctive character of even our earliest spatial perceptions it will be appropriate to animadvert on a mis- leading 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 (1) 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. We can have, or at least we can suppose, an impression which is recognized without being localized ; 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 im- pression 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 un- occupied) space beyond. It is not till a much later stage, after many varying experiences of different impressions similarly local- ized or projected, that even the mere materials are present for the formation of such an abstract conception of space as "spatial reference " implies. 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. In a complex presentation, such as that of an orange or Intuition a piece of wax, may be distinguished the following points oftflin g s - concerning which psychology may be expected to give an account : (a) its reality, (6) its solidity or occupation of space, (c) its permanence, or rather its continuity in time, (d) its unity and complexity, and (e) its substantiality and the connexion of its attributes and powers. Though, in fact, these items are most intimately blended, our exposi- tion will be clearer if we consider each for a moment apart. (a) The terms actuality and reality have each moreActual- than one meaning. Thus what is real, in the sense of il y or material, is opposed to what is mental ; as the existent or rea " tv< actual it is opposed to the non-existent ; and again, what is actual 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 repre- sented, 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. 1 Any examination of this characteristic will be best deferred till we come to deal with ideation generally (see p. 58 below). Meanwhile it may suffice 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, 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 repre- sented 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, as we shall see, turns partly upon the relation of such complex pre- sentation 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 differ- ence, 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. Where no such difference exists we have passed beyond 1 Thus Locke says, "Our simple ideas [i.e., presentations or im- pressions, 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 things, which they copy or represent" (Prin. of Hum. Know., part i. 33).
