An ethical theory developed by German philosopher Immanuel Kant (1724-1804), which holds that the right thing to do is to perform one’s duty for duty’s sake. One’s duty is defined by an ethical principle known as the categorical imperative (CI). According to one version of the CI, one should act according to a maxim that could become a rule for all people. According to another version, one should always treat people as having inherent moral value (or dignity) and never only as objects or things to be used to achieve some end.