Had I the heavens' embroidered cloths, Enwrought with golden and silver light, The blue and the dim and the dark cloths Of night and light and the half light, I would spread the cloths under your feet: But I, being poor, have only my dreams; I have spread my dreams under your feet; Tread softly because you tread on my dreams.
William Butler YeatsA symbol is indeed the only possible expression of some invisible essence, a transparent lamp about a spiritual flame; while allegory is one of many possible representations of an embodied thing, or familiar principle, and belongs to fancy and not to imagination: the one is a revelation, the other an amusement.
William Butler Yeats