conscious in perception of an ego and a non-ego, known together and known in contrast to each other. This is the fact of the duality of consciousness. It is clear and manifest. When I concentrate my attention in the simplest act of perception, I return from my observation with the most irresistible conviction of two facts, or rather two branches of the same fact; that I am and that something different from me exists."[1] "The ego and non-ego, mind and matter, are given together." This fact is 'clear and manifest.'
I am not now asking whether there is any truth in these statements. I simply call attention to the fact that when a philosopher harks back to the plain testimony of consciousness, this is what he harks back to. I think Hamilton was prevented by a philosophical theory from going quite far enough. Certainly the ego which normal consciousness testifies to in 'the simplest act of perception* is usually just the body, and if one is very much interested in something objective, the perception of the ego will not form part of the experience at all. Mill, although unable to be quite so frank as Hamilton, still retains the transcendent object as something whose existence is too evident to be questioned. "I believe that Calcutta exists," he says, "though I do not perceive it, and that it would still exist if every percipient inhabitant were suddenly to leave the place or be struck dead."[2] Calcutta would still be real under these circumstances, for it would remain 'a permanent possibility of sensation.' If the inhabitants return or come to life again, they will perceive Calcutta, and Calcutta was there all the time waiting to be perceived. So Mill reflects.
This 'possibility of sensation' is the classic entrance to the idealism which claims to explain experience in a really profound and consistent way. What, it is asked, is an object of experience while it is mere possibility of sensation? What kind of a positive fact is Calcutta while it is waiting to be perceived? It appears to be taken for granted that it is all the time a 'possibility' of experience, but that if it is really anything at all, it must be something more. The same sturdy instinctive realism which both Hamilton and Mill represent, appears in this request for a further account of the possibility of sensation.
Suppose one were to reply that not even the possibility of sensation exists in the sense in which Mill spoke of it. One could answer, experimentally at least, that so long as Calcutta is not perceived or thought about by human minds, Calcutta simply does not exist. One who made this answer would, no doubt, hasten to add
