Perhaps, it may be thought that the fallacy involved in this argument is too gross for it to be possible that Mr. Bradley should have been guilty of it. But there are other passages in _Appearance and Reality_--particularly what he says about Error --which look to me as if he certainly was guilty of it. I suppose it will be quite obvious to everyone here that it is a fallacy; that the fact that we can think of unicorns is not sufficient to prove that, in any sense at all, there _are_ any unicorns. Yet, I am not sure that I know myself what is _the_ mistake involved in thinking that it _is_ sufficient, and I am going, therefore, to try to put as clearly as I can, what I think it is, in the hope that somebody may be able, if I am wrong, to correct me. The main mistake, I suppose, is the mistake of thinking that the proposition "Unicorns are thought of" is a proposition of the same form as "Lions are hunted"; or the proposition "I am thinking of a unicorn" of the same form as "I am hunting a lion"; or the proposition "Unicorns are objects of thought" of the same form as "Lions are objects of the chase." Of the second proposition in each of these three pairs, it is in fact the case that it could not be true unless there were lions--at least one. Each of them does, in fact, assert both with regard to a certain property--which we will call that of "being a lion"--that there _are_ things which possess it, and also with regard to another--that of being hunted--that some of the things which possess the former possess this property too. But it is obvious enough to common sense that the same is by no means true of the _first_ proposition in each pair, in spite of the fact that their grammatical expression shows no trace of the difference. It is perfectly obvious that if I say "I am thinking of a unicorn," I am not saying both that there is a unicorn and that I am thinking of it, although, if I say "I am hunting a lion," I am saying both that there is a lion, and that I am hunting it. In the former case,