Spinoza's concept of expression — the idea that all things express the one divine substance (God or Nature) in their particular way of being — has influenced poets who see the particular thing (a flower, a stone, a human gesture) as an expression of a deeper reality; Hegel's aesthetics treats art as the sensuous expression of the Idea (Geist) — the artwork is not a decoration but an expression of the truth of a historical moment — and this concept underlies the romantic and modernist claim that the poem expresses something that cannot be said otherwise; A poet reflecting on creative process might use the concept of expression philosophically — is the poem an expression of a prior intention (the expressionist view) or does it constitute the meaning in the making (a more constructivist view)? — and recognize that neither pure expression nor pure construction adequately captures what happens in writing; The Romantic theory of the poem as the expression of the poet's deepest self — Wordsworth's "spontaneous overflow of powerful feelings" — is a philosophical claim about the relationship between interior life and language, and about the authenticity of lyric as the medium of genuine self-expression; Croce's idealist aesthetics, in which art is pure expression and intuition, directly influenced early twentieth-century poetics and the valorization of the lyric as the most complete and direct mode of expressive utterance; Brecht's counter-claim — that the poem expresses not a private self but a social and historical position — challenges the expressionist theory and insists that poetic expression is always already mediated by the social conditions of its production