There is an old saying that God is a circle whose centre is everywhere. If that is true, the saint goes to the centre, the poet and artist to the ring where everything comes round again. The poet must not seek for what is still and fixed, for that has no life for him; and if he did his style would become cold and monotonous, and his sense of beauty faint and sickly, but be content to find his pleasure in all that is for ever passing away that it may come again, in beauty, in the fragile flowers of spring, in momentary heroic passion, in whatever is most fleeting, most impassioned, as it were, for its own perfection, most eager to return in its glory. Yet perhaps he must endure the impermanent a little, for these things return, but not wholly, for no two faces are alike, and, it may be, had we more learned eyes, no two flowers. Is it that all things are made by the struggle of the individual and the world, of the unchanging and the returning, and that the saint and the poet are over all, and that the poet has made his home in the Serpent’s mouth?

Yeats, “In The Serpent’s Mouth,” Discoveries