44. It will perhaps be asked how the understanding can perceive what passes without it, since sensible intuition is a function of a faculty distinct from the understanding? In reply, we shall abstract the questions discussed in the schools concerning the powers of the mind, and be content to remark that whether these be really distinct among themselves, or only one power exercising its activity upon different objects and in different manners, it will be alike necessary to admit a consciousness common to all the faculties. The soul which feels, thinks, recollects, desires, is one and the same, and is alike conscious of all these acts. Whatever be the nature of the faculties by which she performs these acts, she it is that performs them and knows that she performs them. There is then in the soul a single consciousness, the common centre where dwells the inward sense of every activity exercised, and of every affection received, to whatever order they may belong. However, supposing the case the most unfavorable to our theory, that the faculty to which sensible intuition corresponds, is really distinct from the faculty which perceives the relations of the objects offered by sensible intuition; does it therefore follow that the understanding cannot without something intermediate exercise its activity upon objects presented by this intuition? Certainly not. The act of pure understanding and that of sensible intuition, are indeed different, but they meet in consciousness, as in a common field; and there they come in contact, the one exercising its perceptive activity upon the material supplied by the other. CHAPTER VII. THE ACTING INTELLECT OF THE ARISTOTELIANS. 45. I shall now briefly explain the scholastic theory of the manner in which the understanding knows material things. This explanation will show how much reason we had to assert that this doctrine of the schools can be ridiculed only when not understood, and that, whatever its foundation, it cannot be denied to possess an ideological importance. 46. The schoolmen began with this principle of Aristotle, _nihil est in intellectu quod prius non fuerit in sensu_; "There is nothing in the understanding which has not previously been in the senses." Conformably to this principle they maintained that before the soul received impressions from the senses, the understanding was like a clean table upon which nothing had been written: _sicut tabula rasa in qua nihil est scriptum_. According to this doctrine all our knowledge flows from the senses; and at first sight the system of the schools might seem to be very similar to, if not identical with, that of Condillac. Both seek the origin of our cognitions in sensation; both teach that there is no idea in our understanding prior to sensation. But the two systems are, notwithstanding these apparent similarities, very different, and even diametrically opposed.