When I encounter something foreign to me, I do not want to see only that which is my own. Instead, it is like building up the layers of a gorgeous violin varnish: I cook the pigments from different substances and shade it with metal salts, then put it in my little mill and grind it all up into the finest of grain-sized pieces. … If you apply another thin glaze of orange over the first coat, the shade will be intensified but will leave the color rather garish and commonplace. So I borrowed a method from a painter friend of mine to rein in the orange using its complementary hue. No one will ever see that wispy layer of blue, but it will give the orange a wonderfully mellow quality and depth. Likewise, it is important not just to reinforce our thoughts with what is already like them, but to seek out complementary hues and thereby help gently to mature our grasp of the truth. This deepening is joyful when this other new element sounds familiar, and stressful when it departs from your views. But both are necessary: to allow yourself to be strengthened and to allow yourself to be held back. You can tell when a person associates only with like-minded people; his truth will be loud and garish. Only those who let themselves be irritated will truly learn.

— Martin Schleske (tr. Janet Gesme), The Sound of Life’s Unspeakable Beauty, 186

This put in mind another of my favorite passages:

An essential condition for profiting by our reading, whether or ordinary books or those of writers of genius, is to tend always to reconcile our authors instead of setting one against another. The critical spirit has its place; we may have to disentangle opinions and classify men; the method of contrast is then admissible and needs only not to be forced. But when the aim is formation of the mind, personal profit, or even a teacher’s exposition, it is quite a different matter. In these cases it is not the thoughts, but the truths, that interest us; not men’s disputes, but their work and what is lasting in it. It is futile to linger endlessly over differences; the fruitful research is to look for points of contact. … The man who wants to acquire from his authors, not fighting qualities, but truth and penetration, must bring to them this spirit of conciliation and diligent harvesting, the spirit of the bee. Honey is made of many kinds of flowers.

— A. G. Sertillanges, O.P., The Intellectual Life: Its Spirit, Conditions, Methods, 164–65