 The natural law is “universal and invariable” and deals with “the rights and duties which follow [necessarily] from the first principle” (see La loi naturelle; Man and the State, 1951: 97–98) or precept of law—that good is to be done and evil avoided. Nevertheless, while the natural law is “self-evident” (see Man and the State, 1951: 90) and consistent with and confirmed by experience—something which many critics have challenged—Maritain holds that it is not founded on human nature. It is rooted in divine reason and in a transcendent order (i.e., in the eternal law), and is ‘written into’ human nature by God. At times, Maritain appears to hold that natural law acquires its obligatory character only because of its relation to the eternal law; he writes that “natural law is law only because it is participation in Eternal Law” (see Man and the State, 1951: 96). (Some have concluded—perhaps too hastily—that a theory that refers to an Eternal Law must be ultimately theological and cannot be purely philosophical.)