To the passage cited from the Biographia Literaria Coleridge added a caveat:
'Say not that I am recommending abstractions. . . . Paradoxical as it may sound, one of the essential properties of Geometry is not less essential to dramatic excellence; and Aristotle has accordingly required of the poet an involution of the universal in the individual. The chief differences are, that in Geometry it is the universal truth which is uppermost in the consciousness; in poetry the individual form, in which the truth is clothed.'