Cicero: “Shall we not allow old age even the strength to teach the young, to train and equip them for all the duties of life?”

In the matter of a promise one must always consider the meaning and not the mere words.

To this passion for discovering truth there is added a hungering, as it were, for independence, so that a mind well-moulded by Nature is unwilling to be subject to anybody save one who gives rules of conduct or is a teacher of truth or…

So, then, it is truth that is, as it were, the stuff with which this virtue has to deal and on which it employs itself.

But for the most part, people are led to wrong-doing in order to secure some personal end; in this vice, avarice is generally the controlling motive.