What, then, do I attempt to prove in regard to real existence? for surely I attempt to demonstrate something about it. To be sure I do; I endeavour to prove, and I do prove most cogently, what it is, not that it is. Attention to these two words, what and that, may serve to obviate confusion. Suppose that some new and very peculiar animal were discovered, an animal which lived sometimes on the land, sometimes in the sea, and sometimes in the air; and suppose that certain naturalists were employed to investigate its nature. Would they require to prove, in the first instance, that such an animal was? Certainly they would not. There it is before them, and that surely is enough. They would merely have to ascertain what it was. Is it fish, flesh, or fowl? The what here might be a nice point of inquiry, while the that would be an insane one. So in regard to real existence. No man in his senses would require a proof that it is. But a man might very naturally be curious to know what it is. Is real existence mind without matter, or is it matter without mind? Is it thought apart from an intelligent basis, or an intelligent basis apart from all thought? in other words, is real existence any of these items strictly by themselves, and, either actually or possibly, divorced from all relation to one another? Or again, is real existence, mind in union with things or thoughts? Is it matter or something else in connection with intelligence? In other words, is real existence not any of