Now the language we're in when we adopt the sense datum-notation is that we || to forget the difference between the grammar of a statement about sense data & the grammar & an outwardly similar statement about physical objects || reality. (From this point one might go on talking about the misunderstandings which find their expression in such sentences as “we can never see an accurate circle” or “all our sense data are vague”, or about the ideas of absolute position & absolute motion & size in visual space etc. etc..) || as opposed to Euclidian space etc. etc.¤)
     Now we can use || make use of such an expression as “pointing to the appearance of a body” or “pointing to a sense datum”. Roughly speaking this sort of pointing comes to the same as sighting say along the barrel of a gun. Thus we may point & say “this is the direction in which I see the || my image in the mirror.” One can also use such an expression as the appearance or sense datum of my finger points to the sense datum of the tree etc. It is a different case however when I point say to a sound || where a sound seems to come from or when on being asked point to your || my forehead I do so with closed eyes etc.
     Now when in the solipsistic way I say the sentence “this is what's really seen” I point before me & it is essential that I point visually. If I pointed sideways or behind me as it were to things which I don't see the pointing would in this case be meaningless to me it would not be pointing in the sense in which I wish to point. But this means that when I point before me saying “this is what's really seen” although I make the movement || gesture of pointing I don't make any use of it for I don't point to one thing as opposed to another at all. (This is almost as though travelling in a car & feeling in a great hurry || What we || I do is similar to this: when we travel in a car & feel in a great hurry I instinctively press against something in front of me as though I could shove || push the car from the || its inside.)
     If it made || makes sense to say “I see this” or “this is seen”, pointing to what I see, it makes sense to say “I see this” or “this is seen” & to point at || to something I don't see. ¥⋎ And therefore || in this way the solipsist's “only this is really seen” reminds us of a tautology.