in the ethics of the 18th-century German philosopher Immanuel Kant (Kant, Immanuel), founder of critical philosophy, a moral law that is unconditional or absolute for all agents, the validity or claim of which does not depend on any ulterior motive or end. “Thou shalt not steal,” for example, is categorical as distinct from the hypothetical imperatives associated with desire, such as “Do not steal if you want to be popular.” For Kant there was only one such categorical imperative, which he formulated in various ways. “Act only according to that maxim by which you can at the same time will that it should become a universal law” is a purely formal or logical statement and expresses the condition of the rationality of conduct rather than that of its morality, which is expressed in another Kantian formula: “So act as to treat humanity, whether in your own person or in another, always as an end, and never as only a means.”