20.

Zoom out. Alexander Bain claims that the paragraph constitutes the minimal element of writing — what he calls a “division of discourse”: i.e., a main unit of thought, defined by its “unity of purpose” (in a manner that recalls the rigour of the poetic stanza).³¹ Bain argues that the paragraph integrates otherwise disparate sentences, all of which must unite to develop a single thesis about a topic made prominent in the first of its sentences;³² hence, the paragraph possesses a “unity” that does not digress from a single stated topic, but that instead elaborates upon a theme in cogent detail. I might note that because the paragraph takes on the properties of a small essay (complete with topical preface, logical comment, and summary closure), paragraphs in an essay partake of the Droste effect (like a fractal), imitating, in miniature, the whole of which they are a piece.