plausible, I will now offer two pieces of evidence. The first is that language offers us no means of referring to such objects as ‘blue’ and ‘green’ and ‘sweet,’ except by calling them sensations: it is an obvious violation of language to call them ‘things’ or ‘objects’ or ‘terms’. And similarly we have no natural means of referring to such objects as ‘causality’ or ‘likeness’ or ‘identity,’ except by calling them ‘ideas’ or ‘notions’ or ‘conceptions’. But it is hardly likely that if philosophers had clearly distinguished in the past between a sensation or idea and what I have called its object, there should have been no separate name for the latter. They have always used the same name for these two different ‘things’ (if I may call them so); and hence there is some probability that they have supposed these ‘things’ not to be two and different, but one and the same. And, secondly, there is a very good reason why they should have supposed so, in the fact that when we refer to introspection and try to discover what the sensation of blue is, it is very easy to suppose that we have before us only a single term. The term ‘blue’ is easy enough to distinguish, but the other element which I have called ‘consciousness’—that which sensation of blue has in common with sensation of green—is extremely difficult to fix. That many people fail to distinguish it at all is sufficiently shown by the fact that there are materialists. And, in general, that which makes the sensation of blue a mental fact seems to escape us; it seems, if I may use a metaphor, to be transparent—we look through it and see nothing but the blue; we may be convinced that there is something, but what it is no philosopher, I think, has yet clearly recognised.
But this was a digression. The point I had established so far was that in every sensation or idea we must distinguish two elements, (1) the ‘object,’ or that in which one differs from another; and (2) ‘consciousness,’ or that which all have in common—that which makes them sensations or mental facts. This being so, it followed that when a sensation or idea exists, we have to choose between the alternatives that either object alone or consciousness alone or both exist; and I showed that of these alternatives one, namely that the object only exists, is excluded by the fact that what we mean to assert is certainly the existence of a mental fact. There remains the question: Do both exist? Or does the consciousness alone? And to this question one answer has hitherto been given universally: That both exist.
This answer follows from the analysis hitherto accepted of the relation of what I have called ‘object’ to ‘conscious-
