Three qualities of beauty

I think I might just scrap all of my syllabus explanations regarding how I grade essays and short stories in my writing classes. I'll just replace those with this passage from Umberto Eco's The Name of the Rose:

For three things concur in creating beauty:

first of all integrity or perfection,

and for this reason we consider ugly

all incomplete things;

then proper proportion or consonance;

and finally clarity and light,

and in fact we call beautiful

those things of definite color.

— Adso, in The Name of the Rose by Umberto Eco