12) (The private visual image.) B is trained to describe his afterimage when he has looked say into a bright red light. He is made to look into the light, & then to shut his eyes & he is then asked “What do you see?”. This question before was put to him only if he looked at physical objects. We suppose he reacts by a description of what he sees with closed eyes.— But halt! This description of the training seems wrong for what if

I had had to describe my own, not B's, training. Would I then also have said: “I reacted to the question by …” & not rather: “When I had closed my eyes I saw an image & described it”. If I say “I saw an image & described it I say this as opposed to the case where| in which I gave a description without seeing an image. (I might have lied or not.) Now we could of course also distinguish these cases if B describes an afterimage. But we don't wish to consider now cases in which the mechanism of lying plays any part. For if you say “I always know whether I am lying but not whether the other person is”, I say: in the case I'm considering I can't be said to know that I'm not lying, or let us say not saying the untruth, because the dilemma saying the truth or the untruth is in this case unknown to me. Remember that when I'm asked “what do you see here” I don't always ask myself: “Now shall I say the truth or something else?” If you say “but surely if you in fact speak the truth then you did see something & you saw what you said you saw”. I answer: How can I know that I see what I say I see? Do I have a criterium one for the ¿colour¿ I see actually being red?