How to read a book II

He who regards conversation as a battle can win only by being an antagonist, only by disagreeing successfully, whether he is right or wrong. The reader who approaches a book in this spirit reads it only to find something he can disagree with. For the disputations and contentious, a bone can always be found to pick on. (pg. 245)

(...) But if he realizes that the only profit in conversation with live or dead teachers, is what one can learn from them, if he realizes that you win only by gaining knowledge, not by knocking the other fellow down, he may see the futility of mere contentiousness. (pg. 246)

The ignorant often foolishly disagree with the learned about matters exceeding their knowledge. (pg. 247)

(...)The trouble is that many people regard disagreement as unrelated to either teaching or being taught. They think that everything is just a matter of opinion. I have mine. You have yours. Our right to our opinions is as inviolable as our right to private property. On such a view, communication cannot be profitable if the profit to be gained is an increase in knowledge. Conversation is hardly better than a ping-pong game of opposed opinions, a game in which no one keeps score, no one wins, and everyone is satisfied because he ends up holding the same opinions he started with.

I cannot take this view. I think that knowledge can be communicated and that discussion can result in learning. (pg. 248) 

If an author does not give reasons for his propositions, they can be treated only as expressions of opinion on his part. The reader who does not distinguish between the reasoned statement of knowledge and the flat expression of opinion is not reading to learn. He is at most interested in the author's personality and is using the book as a case history. Such a reader will, of course, neither agree nor disagree. He does not judge the book but the author. (pg. 249)

 The great writers have always been great readers, but that does not mean that they read all the books which, in their day, were listed as the great and indispensable ones. In many cases, they read fewer books than are now required in some of our better colleges, but what they did read, they read well. Because they had mastered these books, they became peers with their authors. They were entitled to become authorities in their own right. In the natural course of events, a good student frequently becomes a teacher, and so, too, a good reader becomes an author. (pg. 264)

Clarissa Lake - Mortimer J. Adler - How to Read a Book: The Etiquette of Talking Back and The Things the Reader Can say - Simon and Schuster - New York, 1966