Retreat, as all these seekers testify, is a richly textured affair, harboring something of exploration, something of escape, and something of life-and-death struggle. Whatever the mix, one truth abides: retreat is neither whim nor luxury nor self-indulgence, but a rock-bottom staple of a healthy life. We need retreat as surely as we need oxygen or protein.
— Philip Zaleski, The Recollected Heart