O wretched man, wretched not just because of what you are, but also because you do not know how wretched you are!
Marcus Tullius CiceroThe evil implanted in man by nature spreads so imperceptibly, when the habit of wrong-doing is unchecked, that he himself can set no limit to his shamelessness.
Marcus Tullius CiceroSince an intelligence common to us all makes things known to us and formulates them in our minds, honorable actions are ascribed by us to virtue, and dishonorable actions to vice; and only a madman would conclude that these judgments are matters of opinion, and not fixed by nature.
Marcus Tullius Cicero