your mind a 'thing' or 'image' of which blue is the content. To be aware of the sensation of blue is not to be aware of a mental image—of a "thing," of which 'blue' and some other element are constituent parts in the same sense in which blue and glass are constituents of a blue bead. It is to be aware of an awareness of blue; awareness being used, in both cases, in exactly the same sense. This element, we have seen, is certainly neglected by the 'content' theory: that theory entirely fails to express the fact that there is, in the sensation of blue, this unique relation between blue and the other constituent. And what I contend is that this omission is not mere negligence of expression, but is due to the fact that though philosophers have recognised that something distinct is meant by consciousness, they have never yet had a clear conception of what that something is. They have not been able to hold it and blue before their minds and to compare them, in the same way in which they can compare blue and green. And this for the reason I gave above: namely that the moment we try to fix our attention upon consciousness and to see what, distinctly, it is, it seems to vanish: it seems as if we had before us a mere emptiness. When we try to introspect the sensation of blue, all we can see is the blue: the other element is as if it were diaphanous. Yet it can be distinguished if we look attentively enough, and if we know that there is something to look for. My main object in this paragraph has been to try to make the reader see it; but I fear I shall have succeeded very ill.

It being the case, then, that the sensation of blue includes in its analysis, beside blue, both a unique element 'awareness' and a unique relation of this element to blue, I can make plain what I meant by asserting, as two distinct propositions, (1) that blue is probably not part of the content of the sensation at all, and (2) that, even it were, the sensation would nevertheless not be the sensation of blue, if blue had only this relation to it. The first hypothesis may now be expressed by saying that, if it were true, then, when the sensation of blue exists, there exists a blue awareness: offence may be taken at the expression, but yet it expresses just what should be and is meant by saying that blue is, in this case, a content of consciousness or experience. Whether or not, when I have the sensation of blue, my consciousness or awareness is thus blue, my introspection does not enable me to decide with certainty: I only see no reason for thinking that it is. But whether it is or not, the point is unimportant, for introspection does enable me to decide that something else is also true: namely that I am aware of blue, and by this I mean, that my awareness has to blue a quite different and distinct relation. It is possible, I admit, that my awareness is blue as well as being of blue: but what I am quite sure of is that it is of blue; that it has to blue the simple and unique relation the existence of which alone justifies us in distinguishing knowledge of a thing from the thing known, indeed in distinguishing mind from matter. And this result I may express by saying that what is called the content of a sensation is in very truth what I originally called it—the sensation's object.

But, if all this be true, what follows?

Idealists admit that some things really exist of which they are not aware: there are some things, they hold, which are not inseparable aspects of their experience, even if they be inseparable aspects of some experience. They further hold that some of the things of which they are sometimes aware do really exist, even when they are not aware of them: they hold for instance that they are sometimes aware of other minds, which continue to exist even when they are not aware of them. They are, therefore, sometimes aware of something which is not an inseparable aspect of their own experience. They do know some things which are not a mere part or content of their experience. And what my analysis of sensation has been designed to show is, that whenever I have a mere sensation or idea, the fact is that I am then aware of something which is equally and in the same sense not an inseparable aspect of my experience. The awareness which I have maintained to be included in sensation is the very same unique fact which constitutes every kind of knowledge: "blue" is as much an object, and as little a mere content, of my experience, when I experience it, as the most exalted and independent real thing of which I am ever aware. There is, therefore, no question of how we are to "get outside the circle of our own ideas and sensations." Merely to have a sensation is already to be outside that circle. It is to know something which is as truly and really not a part of my experience, as anything which I can ever know.

Now I think I am not mistaken in asserting that the reason why Idealists suppose that everything which is must be an inseparable aspect of some experience, is that they suppose some things, at least, to be inseparable aspects of their experience. And there is certainly nothing which they are so firmly convinced to be an inseparable aspect of their experience as what they call the content of their ideas and sensations. If, therefore, this turns out in every case, whether it be also the content or not, to be at least not an inseparable aspect of the experience of it, it will be readily admitted that nothing else which we experience ever is such an inseparable aspect. But if we never experience anything but what is not an inseparable aspect of that experience, how can we infer that anything whatever, let alone everything, is an inseparable aspect of any experience? How utterly unfounded is the assumption that "esse is percipi" appears in the clearest light.

But further I think it may be seen that if the object of an Idealist's sensation were, as he supposes, not the object but merely the content of that sensation, if, that is to say, it really were an inseparable aspect of his experience, each Idealist could never be aware either of himself or of any other real thing. For the relation of a sensation to its object is certainly the same as that of any other instance of experience to its object; and this, I think, is generally admitted even by Idealists: they state as readily that what is judged or thought or perceived is the content of that judgment or thought or perception, as that blue Is the content of the sensation of blue. But, if so, then when any Idealist thinks he is aware of himself or of any one else, this cannot really be the case. The fact Is, on his own theory, that himself and that other person are in reality mere contents of an awareness, which is aware of nothing whatever. All that can be said is that there is an awareness in him, with a certain content: it can never be true that there is in him a consciousness of anything. And similarly he is never aware either of the fact that he exists or that reality is spiritual. The real fact, which he describes in those terms, is that his existence and the spirituality of reality are contents of an awareness, which is aware of nothing—certainly not, then, of it own content.

And further if everything, of which he thinks he is aware, is in reality merely a content of his own experience he has certainly no reason for holding that anything does exist except himself: it will, of course, be possible that other persons do exist; solipsism will not be necessarily true; but he cannot