I ran across great definitions of virtue and vice in today’s Office of Readings. Here is what St. Basil the Great said (my translation of the Italian text):
“In fact, the definition of vice is this: the evil use, alien to the precepts of the Lord, of the abilities that He has given to us to do the good. On the contrary, the definition of virtue that God wants from us is: the right use of these same abilities, that derive from a good conscience according to the mandate of the Lord.” — Basil the Great, Response 2, 1; PG 31
Interestingly, St. Basil talked about virtue and vice in the middle of his thoughts on the strength of love in us, the inexorable desire we all have toward love. He called love a natural instinct, a desire for all that is good and beautiful which finds its fulfillment in the beauty of God Himself.
Yes, the basis of the moral life is the orientation toward the True and the Beautiful, who is God. The moral life is a life based on excellence, and the call to excellence. The moral life is not primarily a negation nor is it a privation of something. The moral life is a life of freedom!