"The Greek name for a butterfly is Psyche, and the same word means the soul. There is no illustration of the immortality of the soul so striking and beautiful as the butterfly, bursting on brilliant wings from the tomb in which it has lain, after a dull, grovelling caterpillar existence, to flutter in the blaze of day and feed on the most fragrant and delicate productions of the spring. Psyche, then, is the human soul, which is purified by sufferings and misfortunes, and is thus prepared for the enjoyment of true and pure happiness" (p. 112, n.1).
Bulfinch, Thomas. The Age of Fable. 1855. David McKay, 1898.