No matter how often one tries to pin down what Romanticism is all about, or the difference between Classicism and Romanticism (in the critical, not the historical, sense, since, as has been pointed out, many of the canonical Greek and Roman writers were deeply "Romantic"), one's ideas on this subject are always in the process of growing or taking on added dimensions. Some things you simply have to repeat to yourself over and over. For the most part, I think it is extremely difficult to transport oneself mentally to the era in which "Classical" standards reigned. Emotions, fantasy, inspiration, even egoism were all harnessed, encased in form or ritual or convention. Such restraint is evident today mostly in politics, in conservative thought.
I have been reading a slender but rich book on this subject by F.L. Lucas, from 1936, entitled The Decline and Fall of the Romantic Ideal. Lucas is quite ecumenical, opening in highly satisfactory fashion by quoting a poem by Heine, the one beginning "Ein Fichtenbaum steht einsam/ Im Norden auf kahler Höh." Besides English poetry, Lucas ranges widely into other European languages and is also not restricted to the turn of the 19th century. Not only Wordsworth and Chateaubriand, but also, e.g., Housmann and Baudelaire.
I think there is a connection between the rise of Romanticism in art and literature in the late 18th century and the sublime, on which I have posted frequently. The connection is the rise of taste and of individual "judgment" in the arts. Power passed from the former arbiters. Initially criticism sought to anchor judgment in reason, which was a universal human capacity, but in time there was a revolt against reason's seeming dictates. Lucas introduces charming figurative language to distinguish between classicism and romanticism. Of the former he writes, elliptically: "Grace, self-knowledge, self-control; the sense of form, the easy wearing of the chains of art hidden under flowers, as with some sculptured group that fills with life and litheness its straitened prison in the triangle of a pediment." Of the latter: "Remoteness, the sad delight of desolation, silence and the supernatural, winter and dreariness; vampirine love and stolen trysts, the flowering of passion and the death of beauty."
He then goes on to explore what the "psychological differences" between the two. Drawing to an extent on Freud, he writes of the reconciliation by the "art of life" of two conflicting forces: the instinctive impulse of the human animal versus the influences of other human beings, the latter of which become second nature, so that "A man not only likes or dislikes certain things; he likes or dislikes himself for liking or disliking them." Romanticism is an attempt "to drown this difference and liberate the unconscious life." Venturing an "Aristotelian definition" of Romantic literature, he writes: "a dream-picture of life; providing sustenance and fulfilment for impulses cramped by society or reality."
I am trying to fit Goethe in here, since there is so much that fits with Lucas's exposition, and I speak not merely of the Goethe of the Sturm und Drang years, when he was affected by Herder's ideas concerning the priestly character of primitive poetry and the delights of common, realistic detail. Lucas mentions the dependence of Romantic writers on inspiration and their disinclination to revise. It is true that Goethe went back and revised his early works, in particular The Sorrows of Young Werther, in the period when he was beginning to work against his Romantic tendencies and to exercise more control over his imagination. Otherwise, however, Goethe was not a great reviser. He simply added on, as in the case of Faust. He hated "correcting" -- or being corrected.
While Goethe recoiled from "fantastic" in the productions of contemporary German poets and their pilgrimages to the Middle Ages, he wrote much poetry set in distant times and places, the West-East Divan being the most prominent example. And "vampirine love": how about The Bride of Corinth? There is also something lacking in Goethe's other three novels, namely, a plot. Lucas writes of "the quiet sympathy a writer needs in order to observe and delineate characters other than his own or shadows of his own." Goethe, unlike Jane Austen, lacks that sympathy.
Goethe was, however, vigilant against excess, against the "airy-fairy." If he thought reality left much to be desired, he relentlessly came to terms with that lack. He was able to create beautiful poetry while wearing, as Lucas writes, "a stiff shirt front." A Romantic in the shape of a Classic.