Page:Russell - The Problems of Philosophy, 1912.djvu/83

Rh what sort of reason there is, let us consider for a moment what our acquaintance with particular thoughts really involves.

When I am acquainted with "my seeing the sun," it seems plain that I am acquainted with two different things in relation to each other. On the one hand there is the sense-datum which represents the sun to me, on the other hand there is that which sees this sense-datum. All acquaintance, such as my acquaintance with the sense-datum which represents the sun, seems obviously a relation between the person acquainted and the object with which the person is acquainted. When a case of acquaintance is one with which I can be acquainted (as I am acquainted with my acquaintance with the sense-datum representing the sun), it is plain that the person acquainted is myself. Thus, when I am acquainted with my seeing the sun, the whole fact with which I am acquainted is "Self-acquainted-with-sense-datum."

Further, we know the truth "I am acquainted with this sense-datum." It is hard to see how we could know this truth, or