 The main sources for Erasmus’ concepts of piety and the philosophy centered on Christ are his Enchiridion Militis Christiani (Handbook of the Christian Soldier, 1503) with its prefatory letter to the 1518 edition (Ep. 858; CWE 6), the Paraclesis (Summons, 1516) and, perhaps surprisingly, his lampoon of human foibles, Moriae Encomium (The Praise of Folly, 1511). As he said in reply to indignant critics of his famous jeu d’esprit: