Deborah Eisenberg, from "The Art of Fiction No. 218" in The Paris Review:
Perhaps I should be more suspicious of my belief that there is inherent value in literature. It could be pure, self-serving, soft-brained romanticism, the belief that probing the most delicate and subtle areas of the mind by, say, listening to music or reading will develop what is human in you. There are abundant examples of reactionary, loony, virulently prejudiced artists and art lovers, so one can hardly insist that art is definitively good for the brain. But I believe that a lack of art is really bad for the brain. Art itself is inherently subversive. It's destabilizing. It undermines, rather than reinforces, what you already know and what you already think. It is the opposite of propaganda. It ventures into distant ambiguities, it dismantles the received in your brain and expands and refines what you can experience.
The harm Eisenberg refers to, from the lack of art, is like the lack of an essential nutrient, a vitamin or mineral. That which knocks your perspective, your received narrative, your continous rewrite of the story of your world into a veer away from the seductive comfort of obedience is essential. Those who make art do the work of providing the tools for this useful derangement. By the very act of attending to art, you subvert the status quo, and the status quo never has your wellbeing in mind. Art forces a perturbation in the gravitational force of power. These perturbations are tiny, but they create space for free minds to live and work.