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Stranger
Str. Now since some things will commingle and others will not, they are in much the same condition as the letters of the alphabet; for some of these do not fit each other, and others do.
Theaetetus
Theaet. Of course.
Stranger
Str. And the vowels, to a greater degree than the others, run through them all as a bond, so that without one of the vowels the other letters cannot be joined one to another.
Theaetetus
Theaet. Certainly.
Stranger
Str. Now does everybody know which letters can join with which others? Or does he who is to join them properly have need of art?
5
Theaetetus
Theaet. He has need of art.
Theaetetus
Theaet. The art of grammar.
Stranger
Str. And is not the same true in connection with high and low sounds? Is not he who has the art to know the sounds which mingle and those which do not, musical, and he who does not know unmusical?
Theaetetus
Theaet. Yes.
10
Stranger
Str. And we shall find similar conditions, then, in all the other arts and processes which are devoid of art?
Theaetetus
Theaet. Of course.
Stranger
Str. Now since we have agreed that the classes or genera also commingle with one another, or do not commingle, in the same way, must not he possess some science and proceed by the processes of reason who is to show correctly which of the classes harmonize with which, and which reject one another, and also if he is to show whether there are some elements extending through all and holding them together so that they can mingle, and again, when they separate, whether there are other universal causes of separation?
