They are their own monuments, as is this quietly thrilling sentence. - Stanley Fish

The word "essay" means to try out, test, probe. In the essay style, successive clauses and sentences are not produced by an overarching logic, but by association; the impression that prose gives is that it can go anywhere in a manner wholly unpredictable.

It may sound paradoxical, but verbal fluency is the product of many hours spent writing about nothing, just as musical fluency is the product of hours spent repeating scales.

People write or speak sentences in order to produce an effect, and the success of a sentence is measured by the degree to which the desired effect has been achieved.