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.
Mortimer AdlerIn the case of good books, the point is not to see how many of them you can get through, but how many can get through to you.
Mortimer AdlerA lecture has been well described as the process whereby the notes of the teacher become the notes of the student without passing through the mind of either.
Mortimer Adler