. . .perfection is not arrived at simply by self-denial, and the giving up of all our goods, and the casting away of honours, unless there is that charity, the details of which the Apostle describes, which consists in purity of heart alone. For “not to be envious,” “not to be puffed up, not to be angry, not to do any wrong, not to seek one’s own, not to rejoice in iniquity, not to think evil” etc., what is all this except ever to offer to God a perfect and clean heart, and to keep it free from all disturbances?
John Cassian
The Conferences, I:VI
