Page:Principia Ethica 1922.djvu/168

134 seems to have had great influence in causing acceptance of the view that to be true is the same thing as to be cognised.

This confusion is due to a failure to observe that when we say we have a sensation or perception or that we know a thing, we mean to assert not only that our mind is cognitive, but also that that which it cognises is true. It is not observed that the usage of these words is such that, if a thing be untrue, that fact alone is sufficient to justify us in saying that the person who says he perceives or knows it, does not perceive or know it, without our either enquiring whether, or assuming that, his state of mind differs in any respect from what it would have been had he perceived or known. By this denial we do not accuse him of an error in introspection, even if there was such an error: we do not deny that he was aware of a certain object, nor even that his state of mind was exactly such as he took it to be: we merely deny that the object, of which he was aware, had a certain property. It is, however, commonly supposed that when we assert a thing to be perceived or known, we are asserting one fact only; and since of the two facts which we really assert, the existence of a psychical state is by far the easier to distinguish, it is supposed that this is the only one which we do assert. Thus perception and sensation have come to be regarded as if they denoted certain states of mind and nothing more; a mistake which was the easier to make since the commonest state of mind, to which we give a name which does not imply that its object is true, namely imagination, may, with some plausibility, be supposed to differ from sensation and perception not only in the property possessed by its object, but also in its character as a state of mind. It has thus come to be supposed that the only difference between perception and imagination, by which they can be defined, must be a merely psychical difference: and, if this were the case, it would follow at once that to be true was identical with being cognised in a certain way; since the assertion that a thing is perceived does certainly include the assertion that it is true, and if, nevertheless, that it is perceived means only that the mind has a certain attitude towards it, then its truth must be identical with the fact that it is regarded in this way. We may, then, attribute