Georges de Feure, The Voice of Evil, 1895
Symbolism was largely a reaction against Naturalism and Realism, anti-idealistic movements which attempted to capture reality in its gritty particularity, and to elevate the humble and the ordinary over the ideal. These movements invited a reaction in favour of spirituality, the imagination, and dreams; the path to Symbolism begins with that reaction. Some writers, such as Joris-Karl Huysmans, began as naturalists before moving in the direction of Symbolism; for Huysmans, this change reflected his awakening interest in religion and spirituality.
In literature, the movement has its roots in Les Fleurs du mal (The Flowers of Evil, 1857) by Charles Baudelaire. The aesthetic was developed by Stéphane Mallarmé and Paul Verlaine during the 1860s and '70s. In the 1880s, the esthetic was articulated through a series of manifestoes and attracted a generation of writers. The works of Edgar Allan Poe, which Baudelaire greatly admired and translated into French, were a significant influence and the source of many stock tropes and images. Distinct from the movement in literature, Symbolism in art represents an outgrowth of the darker, gothic, side of Romanticism; but where Romanticism was impetuous and rebellious, Symbolist art was static and hieratic.
Ferdinand Hodler, Night, 1890
The Symbolist Manifesto
Symbolists believed that art should aim to capture more absolute truths which could only be accessed by indirect methods. Thus, they wrote in a highly metaphorical and suggestive manner, endowing particular images or objects with symbolic meaning. The Symbolist manifesto ("Le Symbolisme", Le Figaro, 18 Sept 1886) was published in 1886 by Jean Moréas. Moréas announced that Symbolism was hostile to "plain meanings, declamations, false sentimentality and matter-of-fact description," and that its goal instead was to "clothe the Ideal in a perceptible form" whose "goal was not in itself, but whose sole purpose was to express the Ideal":
Ainsi, dans cet art, les tableaux de la nature, les actions des humains, tous les phénomènes concrets ne sauraient se manifester eux-mêmes ; ce sont là des apparences sensibles destinées à représenter leurs affinités ésotériques avec des Idées primordiales.
(In this art, scenes from nature, human activities, and all other real world phenomena will not be described for their own sake; here, they are perceptible surfaces created to represent their esoteric affinities with the primordial Ideals.)
Néstor, Poem of the Atlantic, 1917