Is there then in the object, as thou usually conceivest of it, anything more than its red colour, its smooth surface, and so on; in short, anything besides those characteristic marks which thou obtainest through immediate sensation?
I. I believe that there is: besides these attributes there is yet the thing itself to which they belong; the substratum which supports these attributes.
Spirit. But through what sense dost thou perceive this substratum of these attributes? Dost thou see it, feel it, hear it; or is there perhaps a special sense for its perception?
I. No. I think that I see and feel it.
Spirit. Indeed! Let us examine this more closely. Art thou then ever conscious of thy sight in itself, or at all times only of determinate acts of sight?
I. I have always a determinate sensation of sight.
Spirit. And what is this determinate sensation of sight, with respect to that object there?
I. That of red colour.
Spirit. And this red is something positive, a simple sensation, a specific state of thyself?
I. This I have understood.
Spirit. Thou shouldst therefore see the red in itself as simple, as a mathematical point, and thou dost see it only as such. In thee at least, as an affection of thyself, it is obviously a simple, determinate state, without connexion with anything else,—which we can only describe as a mathematical point. Or dost thou find it otherwise?
I. I must admit that such is the case.
Spirit. But now thou spreadest this simple red over a broad surface, which thou assuredly dost not see, since
