What happiness to sit in intimate conversation with someone of like mind, warmed by candid discussion of the amusing and fleeting ways of this world…but such a friend is hard to find, and instead you sit there doing your best to fit in with whatever the other is saying, feeling deeply alone.

There is some pleasure to be had from agreeing with the other in general talk that interests you both, but it’s better if he takes a slightly different position from yours. ‘No, I can’t agree with that,’ you’ll say to each other combatively, and you’ll fall into arguing the matter out. This sort of lively discussion is a pleasant way to pass the idle hours, but in fact most people tend to grumble about things different from oneself, and though you can put up with the usual boring platitudes, such men are far indeed from the true friend after your own heart, and leave you feeling quite forlorn.

— Yoshida Kenko, Essays in Idleness


He that wrestles with us strengthens our nerves, and sharpens our skill. Our antagonist is our helper.

— Edmund Burke, Reflections on the Revolution in France


In this sense a book can become very much like a friend: When we enter into a conversation with a friend, do we want that person merely to nod approvingly at everything we say? Of course not: in many cases we want sympathy and agreement, to be sure, but a friend who offered only that would be no friend at all. When we speak our thought, we want more than agreement, we want addition: we want our friend to develop that thought, or to push back at it, if ever so gently. We want to get further along in our understanding of ourselves and our world than we we were when we first spoke, and that cannot happen through mere affirmation. Perhaps the poet William Blake had something like this in mind when he wrote “Opposition is true friendship.” The work that is classic for me is the one that can give me, among other things, that kind of opposition.

— Alan Jacobs, Breaking Bread with the Dead: A Reader’s Guide to a More Tranquil Mind