If practiced to perfection, any virtue can become a vice. Prudence creates niggardliness; honesty, cruelty; self-respect, vainglory; knowledge, condescension; justice, heartlessness; temperance, aridity; chastity, barrenness. In fact, there is no virtue that is not potentially an idol capable of reducing its worshipers to abject solemnity. Which is why the angels are so chary of perfectionism.