WISDOM alone is the right coin with which to deal, and with it everything of real worth is bought and sold. And for it, Temperance and Justice, Fortitude and Prudence, are a kind of preliminary purification.
And those who instituted the Mysteries for us appear to have been by no means contemptible persons, and to have intimated in a veiled manner that whoever descends into Hades uninitiated, and without being a partaker in the Mysteries, shall lie in the mire; but that whoever arrived there purified and initiated, shall dwell with the Gods. Yet, as said those who preside over the Mysteries:
Many are the candidates seeking Initiation, But few are the perfected Initiates. But these few are, in my judgment, true wisdom-lovers; and that I may be of their number I shall leave nothing unattempted, but shall exert myself in all possible ways.
SOCRATES in PLATO’S Phæedo.