It certainly is easy to point out differences between that part of the game in which we applied “lighter” and “darker” to coloured objects and that part in which we applied these words to vowels. In the first part there was comparison of two objects by laying them side by side and looking from one to the other, there was painting a darker or lighter shade than a certain sample given; in the second there was no comparison by the eye, no painting, etc. But when these differences are pointed out, we are still free to speak of two parts of the same game (as we have done just now) or of two different games.