rays cannot pursue their way. Perception is just a phenomenon of the same kind. That which is given is the totality of the images of the material world, with the totality of their internal elements. But if we suppose centres of real, that is to say of spontaneous, activity, the rays which reach it, and which interest that activity, instead of passing through those centres, will appear to be reflected and thus to indicate the outlines of the object which emits them. There is nothing positive here, nothing added to the image, nothing new. The objects merely abandon something of their real action in order to manifest their virtual action—that is to say, in the main, the eventual influence of the living being upon them. Perception therefore resembles those phenomena of reflexion which result from an impeded refraction; it is like an effect of mirage.
This is as much as to say that there is for images merely a difference of degree, and not of kind, betweenSo that representation results from the omission of that in the totality of matter which has no interest for our needs, being and being consciously perceived. The reality of matter consists in the totality of its elements and of their actions of every kind. Our representation of matter is the measure of our possible action upon bodies: it results from the discarding of what has no interest for our needs, or more generally for our functions. In one sense we might say that the perception of any unconscious material point whatever, in its instantaneousness, is infinitely greater and
