 A second moral principle of Herder’s that deserves mention here is the closely related principle of humanity [Humanität], which he develops in the Ideas and the Letters for the Advancement. This principle has both descriptive and normative aspects. Descriptively, it includes an implication of the unity of the human species and of the mere superficiality of racial differences. Normatively, it includes an implication of cosmopolitanism; implications of specific standards of decent treatment (e.g., not killing, physically abusing, or deceiving people); and also functions as a sort of substitute for the ideal of human rights, an ideal that constitutes a closer specification of cosmopolitanism but which Herder tends to shy away from for various reasons (see for this the section on Political Philosophy).