tions, we are forbidden to make a theory of matter in the terms of our sensations.
That is what I think of matter, understood as the inmost structure of bodies—of unknowable and metaphysical matter. I shall not speak of it again; and henceforth when I use the word matter, it will be in quite a different acceptation—it will be empirical and physical matter, such as it appears to us in our sensations. It must therefore be understood that from this moment we change our ground. We leave the world of noumena and enter that of phenomena.
Definition of Mind.—Generally, to define the mind, we oppose the concept of mind to the concept of matter, with the result that we get extremely vague images in our thoughts. It is preferable to replace the concepts by facts, and to proceed to an inventory of all mental phenomena.
Now, in the course of this inventory, we perceive that we have continually to do with two orders of elements, which are united in reality, but which our thought may consider as isolated. One of these elements is represented by those states which we designate by the name of sensations, images, emotions, &c.; the other element is the consciousness of these sensations, the cognition of these images, the fact of experiencing these emotions. It is, in other words, a special activity
