It seems to be owing to this confusion, that the question ‘What is good?’ is thought to be identical with the question ‘What is preferred?’ It is said, with sufficient truth, that you would never know a thing was good unless you preferred it, just as you would never know a thing existed unless you perceived it. But it is added, and this is false, that you would never know a thing was good unless you _knew_ that you preferred it, or that it existed unless you _knew_ that you perceived it. And it is finally added, and this is utterly false, that you cannot distinguish the fact that a thing is good from the fact that you prefer it, or the fact that it exists from the fact that you perceive it. It is often pointed out that I cannot at any given moment distinguish what is true from what I think so: and this is true. But though I cannot distinguish _what_ is true from _what_ I think so, I always can distinguish what I mean by saying _that_ it is true from what I mean by saying _that_ I think so. For I understand the meaning of the supposition that what I think true may nevertheless be false. When, therefore, I assert that it is true I mean to assert something different from the fact that I think so. _What_ I think, namely _that_ something is true, is always quite distinct from the fact that I think it. The assertion that it is true does not even _include_ the assertion that I think it so; although, of course, whenever I do think a thing true, it is, as a matter of fact, also true that I do think it. This tautologous proposition that for a thing to be thought true it is necessary that it should be thought, is, however, commonly identified with the proposition that for a thing to _be_ true it is necessary that it should be thought. A very little reflection should suffice to convince anyone that this identification is erroneous; and a very little more will shew that, if so, we must mean by ‘true’ something which includes no reference to thinking or to any other psychical fact. It may be difficult to discover precisely _what_ we mean--to hold the object in question before us, so as to compare it with other objects: but that we do mean something distinct and unique can no longer be matter of doubt. That ‘to be true’ _means_ to be thought in a certain way is, therefore, certainly false. Yet this assertion plays the most essential part in Kant’s ‘Copernican revolution’ of philosophy, and renders worthless the whole mass of modern literature, to which that revolution has given rise, and which is called Epistemology. Kant held that what was unified in a certain manner by the synthetic activity of thought was _ipso facto_ true: that this was the very meaning of the word. Whereas it is plain that the only connection which can possibly hold between being true and being thought in a certain way, is that the latter should be a _criterion_ or test of the former. In order, however, to establish that it is so, it would be necessary to establish