Cottle was Coleridge's friend and publisher; but also a poet in his own right. I've been reading his 1795 collection of Poems, off and on, to get a sense of what he was about. And I don't mean only to snark; some of his lines are quite good. But some are not. Today's examples are from his long poem in heroic couplets 'John the Baptist':
'The God of Abraham tun'd his mental ear'. No. I can't visualise a 'mental ear' either.
What's a 'latchet'? No matter. Have you ever wondered how it is birds are able to fly? If you guessed: invisible hands, holding them up from underneath then congratulations, you win our star prize!
'Plumy tribes' is particularly wincing.
‘Could a rule be given from without, poetry would cease to be poetry, and sink into a mechanical art. It would be μóρφωσις, not ποίησις. The rules of the IMAGINATION are themselves the very powers of growth and production. The words to which they are reducible, present only the outlines and external appearance of the fruit. A deceptive counterfeit of the superficial form and colours may be elaborated; but the marble peach feels cold and heavy, and children only put it to their mouths.’ [Coleridge, Biographia ch. 18]
‘ποίησις’ (poiēsis) means ‘a making, a creation, a production’ and is used of poetry in Aristotle and Plato. ‘μóρφωσις’ (morphōsis) in essence means the same thing: ‘a shaping, a bringing into shape.’ But Coleridge has in mind the New Testament use of the word as ‘semblance’ or ‘outward appearance’, which the KJV translates as ‘form’: ‘An instructor of the foolish, a teacher of babes, which hast the form [μóρφωσις] of knowledge and of the truth in the law’ [Romans 2:20]; ‘Having a form [μóρφωσις] of godliness, but denying the power thereof: from such turn away’ [2 Timothy 3:5]. I trust that's clear.
There is much more on Coleridge at my other, Coleridgean blog.