One might want to say that the difference between an apple and the colour red is a greater difference than that between an apple and a pear, between red and blue. In the same vein, one might want to say that the philosopher's question “What, really, is a piece of wax?” has greater generality than the more ordinary question “What distinguishes a piece of wax from a piece of soap?” I think Wittgenstein would say that to talk in this way (and it is the same way in each case) is to make the difference at issue seem too slight, so that we fail to see what the difference really amounts to.

I should like to suggest that the following thesis is pervasive and fundamental in Wittgenstein's later teaching.