So Théophile Gautier. The first poet I'm studying in my French symbolists class. He's definitely not a Symbolist himself, being more of a late Romantic than anything. Yet he rejected the loose, undisciplined verse-style of the Romantics and developed a classical form more rigid than even Classicism had demanded. He had a heavy influence on the Symbolists insofar as he relied heavily upon images to transmit an experience, and cultivated what for many early moderns would become the highest poetic virtues: detachment and clear statement (and of course, in that evaluation we see a decided return to elements of the Classical aesthetic as well).
He's most well-known as a precursor to the Parnassians, whose high opinion of themselves can be seen in their group's appelation, which is obviously meant to remind us poor mortals (at that time so woefully in the clutches of romanticism)that they, the true poets, drink at the fonts of inspiration on Mount Parnassus itself, ethereal home of the Muses and source of many poetic marvels. Anyway, they were quite enamored of his doctrine of "L'Art pour l'art" - Art for Art's Sake, a doctrine whose primary thrust was to reject any sense of purpose - such as social commentary, cultural criticism, portrayal of abstract or transcendent truth - in art, saying that for art to be truly pure it must be free from such "ulterior motives". They also cultivated Gautier's example of exact and faultless workmanship as an answer to the excessive sentimentality of Romanticism.
Now the Symbolists rejected the Parnassians' clarity and objectivity as overly realistic (in the sense of being in the style of Realism or Naturalism); they had the notion, rather akin to Keat's concept of negative capability, that art should strive to portray absolute truths which cannot be accessed directly or exhausted by direct and clear imagery. They did, however, love the musicality of Parnassian verse, a quality which Gautier's example had helped the latter to achieve; and they admired his doctrine of "L'Art pour l'art" and his mood of ironic detachment.
That suffices as a basic description, though I'm going to post a poem, for those who can read it, which is a good example of what I mean, and much more revealing than a prose listing of qualities. Analysis may follow in a later post, though I don't promise it, and if it happens, will most likely happen in French anyway, so it won't be much use.