categorical imperative

categorical imperative, in the ethics of the 18th-century German philosopher Immanuel Kant, founder of critical philosophy, a rule of conduct that is unconditional or absolute for all agents, the validity or claim of which does not depend on any desire 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 categorical imperative in the moral realm, which he formulated in two 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.” For further discussion of the role of the categorical imperative in Kant’s moral philosophy, see Immanuel Kant: The Critique of Practical Reason and Ethics: The Continental tradition from Spinoza to Nietzsche: Kant.

(Read Peter Singer’s Britannica entry on ethics.)