... The person who, at any stage of a conversation, disagrees, should at least hope to reach agreement in the end. He should be as much prepared to have his own mind changed as seek to change the mind of another ... No one who looks upon disagreement as an occasion for teaching another should forget that it is also an occasion for being taught.
Mortimer AdlerThe great authors were great readers, and one way to understand them is to read the books they read.
Mortimer AdlerReading 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.
Mortimer AdlerIf your friend wishes to read your 'Plutarch's Lives,' 'Shakespeare,' or 'The Federalist Papers,' tell him gently but firmly, to buy a copy. You will lend him your car or your coat - but your books are as much a part of you as your head or your heart.
Mortimer Adler