Sanity (from ) refers to the soundness, rationality and healthiness of the human mind, as opposed to insanity. A person is not considered sane anymore just if he/she is irrational. In modern society, the terms have become exclusively synonymous with compos mentis , in contrast with non compos mentis, or insane, meaning troubled conscience. A sane mind is nowadays considered healthy both from its analytical -once called rational- and emotional aspects. Furthermore, according to Chesterton, sanity involves wholeness, whereas insanity implies narrowness and brokenness.