En el New York Times: Why You Should Read Books You Hate:

In earlier, blithe days, I'd simply allowed the contents of books to gather agreeably in my head as I read and then file out when I was done. Either I enjoyed a book or I didn't. It was only by burrowing through books that I hated, books that provoked feelings of outrage and indignation, that I truly learned how to read. Defensiveness makes you a better reader, a closer, more skeptical reader: a critic. Arguing with the author in your head forces you to gather opposing evidence. You may find yourself turning to other texts with determination, stowing away facts, fighting against the book at hand. You may find yourself developing a point of view.

Y, en general, con cualquier libro, aunque estemos de acuerdo con él (quien dice libro dice artículo de prensa o cualquier otro tipo de texto o argumento): hay que recibirlo siempre con la sensación de que el autor nos va a intentar convencer de algo.