Socrates Any one may see that there is no disgrace in the mere fact of writing.
Phaedrus Certainly not.
Soc. The disgrace begins when a man writes not well, but badly.
Phaedr. Clearly.
Soc. And what is well and what is badly--need we ask [anyone] to teach us this?

What is Quality? In Zat Ao MM we are told that Quality is what you like (and emphatically not the dismissive just what you like).

In the Essay On Typography, that it is both fitness for purpose and fittingness to mode of life.

These seem as if they are relative, subjective, criteria. Yet the opposite is true. The same definition is given in Round The Bend, but in different language, making plain that Quality is something that we all carry an absolute standard of within us.

Of course, the capacity to use that standard, and the level of skill in doing so is something that varies from individual to individual. Being a skill, the sensing of Quality is something that may be improved by training.