"It was because God wished to bestow on the rational creature the gift of doing good of his own free will and the capacity to exercise free choice, by implanting in man the possibility of choosing either alternative. ... He could not claim to possess the good of his own volition, unless he was the kind of creature that could also have possessed evil. Our most excellent creator wished us to be able to do either but actually to do only one, that is, good, which he also commanded, giving us the capacity to do evil only so that we might do His will by exercising our own. That being so, this very capacity to do evil is also good – good, I say, because it makes the good part better by making it voluntary and independent, not bound by necessity but free to decide for itself."

“Whenever I have to speak on the subject of moral instruction and the conduct of a holy life, it is my practice first to demonstrate the power and quality of human nature.”

“Yet we do not defend the good of nature to such an extent that we claim that it cannot do evil, since we undoubtedly declare also that it is capable of good and evil; we merely try to protect it from an unjust charge, so that we may not seem to be forced to do evil through a fault of our nature, when, in fact, we do neither good nor evil without the exercise of our will and always have the freedom to do one of the two, being always able to do either.”

“When will a man guilty of any crime or sin accept with a tranquil mind that his wickedness is a product of his own will, not of necessity, and allow what he now strives to attribute to nature to be ascribed to his own free choice? It affords endless comfort to transgressors of the divine law if they are able to believe that their failure to do something is due to inability rather than disinclination, since they understand from their natural wisdom that no one can be judged for failing to do the impossible and that what is justifiable on grounds of impossibility is either a small sin or none at all.”

“Love of wealth is insatiable, desire for honour knows no fulfilment; possessions destined to meet with a speedy end are sought endlessly. But divine wisdom, heavenly riches, immortal honours we neglect in our indifference and sloth, and, as for spiritual riches, either we do not touch them at all or, if we get a slight taste of them, we at once suppose that we have had enough. The divine Wisdom invites us to its feasts in quite different terms: Those who eat me, she says, will hunger for more, and those who drink me will thirst for more . No one can have enough of such feasts or ever suffers from squeamishness because he has had too much: the more he drinks from that source the greater will be each man's capacity and eagerness for more.”

“If you depart from evil but fail to do good, you transgress the law, which is fulfilled not simply by abominating evil deeds but also by performing good works.”

“Whenever I have to speak on the subject of moral instruction and conduct of a holy life, it is my practice first to demonstrate the power and quality of human nature and to show what it is capable of achieving, and then to go on to encourage the mind of my listener to consider the idea of different kinds of virtues, in case it may be of little or no profit to him to be summoned to pursue ends which he has perhaps assumed hitherto to be beyond his reach; for we can never end upon the path of virtue unless we have hope as our guide and compassion.”