The deepest need of man, then, is the need to overcome his separateness, to leave the prison of his aloneness. The absolute failure to achieve this aim means insanity, because the panic of complete isolation can be overcome only by such a radical withdrawal from the world outside that the feeling of separation disappears—because the world outside, from which one is separated, has disappeared.
Erich Fromm, The Art of Loving
philosophy, psychology