What we did in these discussions was what we always do when we meet the word “can” in a metaphysical proposition. We show that this proposition hides a grammatical rule. Tha[|t] is to say, we destroy the outward similarity between a metaphysical proposition and an experiential one, and we try to find the form of expression which fulfills a certain craving of the metaphysician which our ordinary language does not fulfill and which, as long as it isn't fulfilled, produces the metaphysical puzzlement. Again, when in a metaphysical sense I say “I must always know when I have pain”, this simply makes the word “know” redundant; and instead of “I know that I have pain”, I can simply say “I have pain”. The matter is different of course if we give the phrase “unconscious pain” sense by fixing experiential criteria for the case in which a man has pain and doesn't know it, and if then we say (rightly or wrongly), that as a matter of fact nobody has ever had pains which he didn't know of.