"As much as it is easier to sin in thought than in deed, so is a war with thoughts more exacting than one with things."

Ὅσον ἐστὶν εὐκοπώτερον τὸ κατὰ διάνοιον ἁμαρτάνειν τοῦ κατ᾿ἐνέργειαν, τοσοῦτόν ἐστι βαρύτερος ὁ διὰ τῶν νοημάτων πόλεμος τοῦ διὰ τῶν πραγμάτων.

     Maximus the Confessor, Four hundred chapters on love 2.72, trans. George C. Berthold, in Maximus Confessor:  selected writings,Classics of Western spirituality (New York:  Paulist Press, 1985), 57.  Capitoli sulla carità, ed. Aldo Ceresa-Gastaldo, Verba seniorum n.s. 3 (Roma : Editrice Studium, 1963), 128; PG 90, col. .  Cf. 1.91:  "the demons' battle with us through thoughts is more severe than that through deeds" (45).