De vitiis nostris scalam nobis facimus, si vitia ipsa calcamus.
(We make for ourselves a ladder of our vices, when we tread under foot the vices themselves.)
St. Augustine (De Ascensione).
I held it truth, with him who sings
To one clear harp in divers tones,
That men may rise on stepping-stones
Of their dead selves to higher things.
Tennyson (In Memoriam).