Turning from such abstract considerations to empirical study of the sensation, the same sort of difficulty reappears. We think we find a dynamic relationship of organic to extra-organic processes; this relationship presents a material aspect, which we call neural activity, and a formal aspect, which we call blue, for instance. But the critic objects that all this is much more than sensation, and that we have read our hypothesis into our data. We must keep to the pure sensation; in that, there is no neural process. So, even as, before, all our attempts to propose a definition of consciousness for analysis were ruled out as begging the question, now every sample of the experience to be observed is rejected as impure. There is no sensation that is pure in such a sense as our critic means, for he means subjectivity that implies no objectivity. If this is more than a word, it is a self-contradiction, since subjectivity is subjectivity only in the fact of correlation with objectivity. Indeed, if our critic were to observe convexity as he proposes that we observe sensation, he would find no implication of concavity in it; nor would he find it convex. His observation would _be_ the convexity; the two would coincide, and so would not be two. Convexity in its essence, as convex, would therein no longer be the object of the observation. You have to get outside of your convexity to observe it and its implication of concavity; just so, you have to get outside of your sensation to know it; in it, you know only the object of it. When convexity is said to imply concavity, convexity is just therein not “pure,” as the sensation is supposed to be. “Pure” convexity, analogous to “pure” sensation or subjectivity, would be convexity without implication of concavity. That would be zero convexity, so to speak--a self-contradiction. Just so, the “pure” sensation, without implication of objectivity, is a fact of consciousness without the essence of consciousness, which is dynamic relatedness to an object. “Pure” consciousness is consciousness of nothing, or no consciousness. If our critic have his way, we have nothing left us to discuss. Let us invite his attention to a discussable phenomenon of our own designating, and definable in some such way as this: the simultaneous belonging of an experience to an organism and to another material fact, say the sky. The two belongings are distinguished by a _sui generis_ difference of direction or relational “sense,” which unambiguously determines the organism to be the subject of the belonging, the sky the object. We have at least as good a right to call this phenomenon by the name of consciousness, or sensation, as our critic has to name that a sensation which he so defines that its definition is contradicted by the naming.