On Choosing Good:

Three principles move us to good: the seeds in our nature, the holy powers, and our will for good. Seeds we have from nature when, for example, we treat others as we wish to be treated by them, or when we see a man in want and in trouble and naturally show compassion to him. Holy powers, when feeling an impulse to some good deed, we find blesses assistance, and are successful. Finally, will for good, when we distinguish good from evil and choose the good.

St. Maximos the Confessor, Second Century on Love, Text #32