What can be accomplished by a few principles is not effected by many. But it seems that everything we see in the world can be accounted for by other principles, supposing God did not exist. For all natural things can be reduced to one principle, which is nature, and all voluntary things can be reduced to one principle, which is human reason, or will. Therefore there is no need to suppose God's existence.
Thomas AquinasIf a man deliberately abstains from wine to such an extent that he does serious harm to his nature, he will not be free from blame.
Thomas Aquinas