This is a shady word, as any scholar investigating its pedigree discovers: so many are its strands of meaning.
Students need to be wary of its use in literary criticism, especially if such writers as Keats, Shelley or Coleridge are described as Romantic Poets; and if romantic is used as an antithesis to classical, then literary criticism begins to go wrong and to mislead.
These poets and their peers never used romantic to refer to themselves, nor were they attempting to renounce classical tradition, as a look at their work reveals. Certainly they were rebels, and their poetry was revolutionary; but what they were rejecting was the convention of adhering to certain compositional forms, and above all the convention that certain matters, especially personal feelings and reverence for the natural world, were not suitable for poetry.
They considered that such rules and constraints had gone too far, to the extent of stifling inspiration, and in the process suppressing poetry itself. That view appears in Sleep and Poetry, where John Keats berates those writers who have turned writing into a mechanical exercise and forgotten that it is a divine gift:
Could all this be forgotten? Yes, a schism
Nurtured by foppery and barbarism,
Made great Apollo blush for this his land.
Men were thought wise who could not understand
His glories: with a puling infant’s force
They sway’d about upon a rocking horse,
And thought it Pegasus. Ah dismal soul’d!
The winds of heaven blew, the ocean roll’d
Its gathering waves—ye felt it not. The blue
Bared its eternal bosom, and the dew
Of summer nights collected still to make
The morning precious: beauty was awake!
Why were ye not awake? But ye were dead
To things ye knew not of, —were closely wed
To musty laws lined out with wretched rule
And compass vile…
A thousand handicraftsmen wore the mask
Of Poesy. Ill-fated, impious race!
That blasphemed the bright Lyrist to his face,
And did not know it…
Great Apollo? His glories? The bright Lyrist…? This was a rejection not of the classical tradition, but of its distortion into pedantry. Later in the poem, Keats denounces Nicolas Boileau, the French poet and author of L’Art Poétique, which laid down rules of form and composition, allegedly on the classical pattern, and even influenced such luminaries as Pope and Dryden.
It seems that Boileau went too far with his constraints; perhaps he, and others, needed to observe the classical requirement of σωφροσύνη and the injunction of μηδὲν ἄγαν.