A 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 YeatsLabor is blossoming or dancing where The body is not bruised to pleasure soul, Nor beauty born out of its own despair, Nor blear-eyed wisdom out of midnight oil. O chestnut tree, great-rooted blossomer, Are you the leaf, the blossom or the bole? O body swayed to music, O brightening glance How can we know the dancer from the dance?
William Butler Yeats