How does Phillip Lopate use imagery in The Art of the Personal Essay: An Anthology from the Classical Era to the Present?

In the essay "Of a Monstrous Child" it seems that the author has chosen the name as a contradictory term. He describes the child in gruesome detail even down to where the child is able to urinate from. The imagery used here is very harsh and creates a picture that is hard to ignore. In addition to the child Montaigne goes on to describe a full grown man he knows that was born missing his genitalia. After describing both of these people Montaigne then says that it cannot be a mistake of nature. Montaigne talks about how it is contrary to custom but not to nature. It appears that Montaigne is chastising people that would call these people mistakes of nature although he does not come out and do so directly.