here we must be satisfied to consider one or two examples that will elucidate the situation for us.
The greatest systems of metaphysics and those that have had the largest number of supporters are "idealistic" systems. What is the doctrine of metaphysical idealism, and why has it such a great fascination for philosophers ? It asserts that the real essence of all things is of the same kind as that which we experience in our own consciousness; and since the data of consciousness have the character of "ideas" their view is called idealism. I think it is very plain how these phrases have to be interpreted. They reveal the philosopher's desire to become as intimately acquainted with all things as he is with the contents of his own consciousness. It is the one place where the self coincides with reality, where the knower is identical with the known. And, so he goes on to argue, if in this one place I discover reality to be "mental" (i.e. to consist of the stuff ideas are made of) I am justified to infer by analogy that the same will be true also of all other parts of reality with which I do not happen to be so intimately acquainted.
After everything we have said about the nature of knowledge the pitiful logic of this reasoning must be clear. It is not, of course, that we would find fault with the inference by analogy, if there were any inference, but actually there is none, as all these sentences are devoid of meaning. We notice the desperate efforts to say something about content: that with which we are immediately acquainted is declared to be "mental". What does this mean? It does not mean anything, for evidently "contents of consciousness", "that with which we are immediately acquainted" and "mental" are, in this context, absolutely equivalent terms, and we are not saying anything, when we predicate one of the other. And we are not saying anything, either, when we predicate one of them of the "real essence" or the "inmost nature" of a thing. For by these latter phrases the metaphysician wishes to indicate the thing as it would be given to us in intuition if we could penetrate into it, if our mind or consciousness could become identical with it; so, by substituting this meaning into the statement of the metaphysician we find him asserting that all things, if they could completely enter into our consciousness, would be mental i.e. contents of our own mind — which would again be nothing but a pitiful tautology, even if the hypothetical part of the sentence had any meaning. But it has no sense at all, for it is nonsense to speak of
