From this indetermination, accepted as a fact, we have been able to infer the necessity of a perception, that is to say, of a variable relation between the living being and the more or less distant influence of the objects which interest it. How is it that this perception is consciousness, and why does everything happen as if this consciousness were born of the internal movements of the cerebral substance?
To answer this question, we will first simplify considerably the conditions under which conscious perception takes place. In fact, there is no perception which is not full of memories. With the immediate and present data of our senses we mingle a thousand details out of our past experience. In most cases these memories supplant our actual perceptions, of which we then retain only a few hints, thus using them merely as 'signs' that recall to us former images. The convenience and the rapidity of perception are bought at this price; but hence also springs every kind of illusion. Let us, for the purposes of study, substitute for this perception, impregnated with our past, a perception that a consciousness would have if it were supposed to be ripe and full-grown, yet confined to the present and absorbed, to the exclusion of all else, in the task of moulding itself upon the external object.—It may be urged that this is an arbitrary hypothesis, and that such an ideal perception, obtained by the
