Suppose I said, “I see this scribble like this”, and while saying “this scribble” I look at it as a mere scribble, and while saying “like this”, I see the face, – – this would come to something like saying, “What at one time appears to me like this at another appears to me like that”, and here the “this” and the “that” would be accompanied by the two different ways of seeing. ‒ ‒ But we must ask ourselves in what game is this sentence with the processes accompanying it to be used. E.g., whom am I telling this? Suppose the answer is, “I'm saying it to myself.” But that is not enough. We are here in the grave danger of believing that we know what to do with a sentence if it looks more or less like one of the common sentences of our language. But here in order not to be deluded we have to ask ourselves: What is the use, say, of the words “this” and “that”? – – or rather, What are the different uses which we make of them? What we call their meaning the meaning of these words is not anything which they have got in them or which is fastened to them irrespective of what use we make of them. Thus it is one use of the word “this” to go along with a gesture pointing to something: We say, “I am seeing the square with the diagonals like this”, pointing to a swastika. And referring to the square with diagonals I might have said, “What at one time appears to me like this at another time appears to me like that .” And this is certainly not the use we made of the sentence in the above case. ‒ ‒ One might think the whole difference between the two cases is this, that in the first the pictures are mental, in the second, real drawings. We should here ask ourselves in what sense we can call mental images pictures, for in some ways they are comparable to drawn or painted pictures, and in others not. It is, e.g., one of the essential points about the use of a “material” picture that we say that it remains the same not only on the ground that it seems to us to be the same, but that we remember that it looked before as it looks now. In fact we shall say under certain circumstances that the picture hasn't changed although it seems to have changed; and we say it hasn't changed because it has been kept in a certain way, certain influences have been kept out. Therefore the expression, “The picture hasn't changed”, is used in a different way when we talk of a material picture on the one hand, and of a mental one on the other. Just as the statement, “These ticks follow at equal intervals”, has got one grammar if the ticks are the tick of a pendulum and the criterion for their regularity is the result of measurements which we have made on our apparatus, and another grammar if the ticks are ticks which we imagine. I might for instance ask the question: When I said to myself, “What at one time appears to me like this, at another … ”, did I recognize the two aspects, this and that, as the same which I got on previous occasions? Or were they new to me and I tried to remember them for future occasions? Or was all that I meant to say, “I can change the aspect of this figure”?