Meaning of "not to say this is a bad kind of poetry" etc. in Wordsworth's Preface to the "Lyrical Ballads"

Question

At one point in the Preface to the Lyrical Ballads (1800), Wordsworth quotes a parody of simple verses by Samuel Johnson and compares it with a stanza from the "Babes in the Wood". Then he writes:

In both of these stanzas the words, and the order of the words, in no respect differ from the most unimpassioned conversation. There are words in both, for example, "the Strand," and "the Town," connected with none but the most familiar ideas; yet the one stanza we admit as admirable, and the other as a fair example of the superlatively contemptible. Whence arises this difference? Not from the metre, not from the language, not from the order of the words; but the matter expressed in Dr. Johnson's stanza is contemptible. The proper method of treating trivial and simple verses to which Dr. Johnson's stanza would be a fair parallelism is not to say this is a bad kind of poetry, or this is not poetry, but this wants sense; it is neither interesting in itself, nor can lead to any thing interesting; the images neither originate in that sane state of feeling which arises out of thought, nor can excite thought or feeling in the Reader. This is the only sensible manner of dealing with such verses: Why trouble yourself about the species till you have previously decided upon the genus? Why take pains to prove that an Ape is not a Newton when it is self-evident that he is not a man.

What are the last two lines referring to? At first, I thought they meant that it's pointless to talk about whether something is good or bad poetry when it is not even poetry in the first place. But just a couple of lines before he says that the right way to deal with trivial verses is "not to say this is a bad kind of poetry, or this is not poetry".

Answer 1

Perhaps changing which words are bolded and italicizing other words will help:

The proper method of treating trivial and simple verses to which Dr. Johnson's stanza would be a fair parallelism is not to say this is a bad kind of poetry, or this is not poetry, but this wants sense; it is neither interesting in itself, nor can lead to any thing interesting; the images neither originate in that sane state of feeling which arises out of thought, nor can excite thought or feeling in the Reader. This is the only sensible manner of dealing with such verses.

What Wordsworth is saying is that it is a mistake to call lines such as those in Dr Johnson's parody "bad poetry". It is even a mistake to claim that those lines are "not poetry". Calling those lines "not poetry" is trivially true, but it's like saying "an ape is not a Newton". Forget about being a Newton (a member of "the species" Homo sapiens), an ape is not even a human (a member of "the genus" Homo).

Wordsworth argues that instead, the correct way to deal with lines like those in Dr Johnson's parody is to call them nonsense: "this wants sense", using "wants" in the sense of "lacks".