We are now in a position to reconsider the restriction which Kant puts on the interpretation of his own dictum that understanding makes nature. This with him means that understanding, as the unifying principle which is the source of relations, acts formatively upon feelings as upon a material given to it from an opposite source called things-in-themselves, rendering them into one system of phenomena called nature, which is the sole object of experience, and to which all judgments as to matters of fact relate. We demur to the independent reality, or reality as determined by something else than thought, which is thus ascribed to feeling. It is not that we would claim any larger function for thought than Kant claims for understanding as separate from feeling, supposing that separation to be once admitted. It is the separation itself that is in question. We do not dispute the validity of Locke's challenge to a man by any amount of thinking to produce a single simple idea to himself. We admit that mere thought can no more produce the facts of feeling, than mere feeling can generate thought. But we deny that there is really such a thing as mere feeling or mere thought. We hold that these phrases represent abstractions to which no reality corresponds, either in the facts of the world or in the consciousness to which those facts are relative. We can attach no meaning to reality, as applied to the world of phenomena, but that of existence under definite and unalterable relations; and we find that it is only for a thinking consciousness that such relations can subsist. Reality of feeling, abstracted from thought, is abstracted from the condition of its being a reality. That great part of our sensitive life is not determined by our thought, that the sensitive life of innumerable beings is wholly undetermined by any thought of theirs or in them, is not in dispute: but this proves nothing as to what that sensitive life really is in nature or in the cosmos of possible experience. It has no place in nature, except as determined by relations which can only exist for a thinking consciousness. For the consciousness which constitutes reality and makes the world one it exists, not in that separateness which belongs to it as an attribute of beings that think only at times or not at all, but as conditioned by a whole which thought in turn conditions. (§ 51 ¶ 1)

As to what consciousness in itself or in its completeness is, we can only make negative statements. That there is such a consciousness is implied in the existence of the world; but what it is we only know through its so far acting in us as to enable us, however partially and interruptedly, to have knowledge of a world or an intelligent experience. In such knowledge or experience there is no mere thought or mere feeling. No feeling enters into it except as qualifying, and qualified by, an interrelated order of which a self-distinguishing subject forms the unifying bond. Thought has no function in it except as constantly co-ordinating ever new appearances in virtue of their presence to that one subject. And we are warranted in holding that, as a mutual independence of thought and feeling has no place in any consciousness on our part, which is capable of apprehending a world or for which a world exists, so it has none in the world-consciousness of which ours is a limited mode. (§ 51 ¶ 2)