To agree without understanding is inane. To disagree without understanding is impudent.

We are selfish when we are exclusively or predominantly concerned with the good for ourselves. We are altruistic when we are exclusively or predominantly concerned with the good of others.

The ultimate end of education is happiness or a good human life, a life enriched by the possession of every kind of good, by the enjoyment of every type of satisfaction.

Angels are able to know and understand better than the human intellect can, precisely because such knowledge and understanding comes to them by way of ideas infused in them by God.

Love consists in giving without getting in return; in giving what is not owed, what is not due the other. That's why true love is never based, as associations for utility or pleasure are, on a fair exchange.

Conjugal love, or the friendship of spouses, persists after sexual desires have weakened, withered, and disappeared.

Reading a book should be a conversation between you and the author. Presumably he knows more about the subject than you do; if not, you probably should not be bothering with his book. But understanding is a two-way operation; the learner has to question himself and question the teacher, once he understands what the teacher is saying. Marking a book is literally an expression of your differences or your agreements with the author. It is the highest respect you can pay him.