A number of seniors gather round the holy Antony for mutual encouragement:
On one occasion a number of the seniors went to the blessed Antony in the Thebaid to confer together in the search for perfection. They continued talking from vespers until daylight, the question of discretion taking up the greater part of the night. The question which they discussed at such length among themselves was: Which virtue or monastic observance could keep a monk unharmed from the attacks of the devil, and surely carry him by assured means on the right path to God? Each one gave his own opinion as to what he thought best. Some said the practice of fasting and vigils, others nakedness and contempt of worldly possessions, others a withdrawn life into the hidden parts of the desert, quite a few put the quest for charity first, which they defined as service to humanity consisting of the pious practice of giving hospitality to brothers and strangers. After spending the greater part of the night in devout discussion of this nature, the blessed Antony at last replied to them all.
“All the things you have mentioned are useful and necessary for anyone thirsting after God. But the countless circumstances and experiences of so many brothers do not allow of us giving precedence to any single one of these virtues. I have often seen brothers who observe certain practices becoming deceived in the end, because they did not observe discretion in the good thing which they had undertaken. The chief cause of their fall has been that far from being governed by their superiors, they failed to grasp the necessity for discretion, which is able to teach a monk a royal road that prevents them from overdoing ascetic practices on the one hand, while safeguarding them from falling into vice on the other. In everything that we do, discretion must come first. We must be quite clear about this: no virtue can be perfectly begun and continued without the grace of discretion.”
After what Antony had said, they all agreed that discretion was the way to lead a monk fearlessly to God step by step, for it ensured that none of the virtues they had talked about could ever become harmful. Discretion is the mother and guardian and governor of every virtue.
De Vitis Patrum. Book IV, Chapter 42 (Cassian, Conference 2, chapter 2)