Examples of perfect, "seraphic" poets : Holderlin, Pushkin, Marvell, Keats, Donne, Rilke, Celan, Mandelstam, Whitman, Dickinson...

what makes them perfect? At their best, they make verse sing on all levels. Intellectual music. Going to the edge of the human (the upper limit).

Mystery of when & how nations & cultures evolve perfect poets. Dialect of the tribe; shared meanings & forms of play.