Categorical Imperative, term coined by the German philosopher Immanuel Kant to designate what he considered an unconditional, necessary, and absolute moral law, which he believed to be the rational foundation for moral conduct. “So act,” he wrote, “that the moral of thy doing shall, at thy will, become universal law.” In other words, moral choices are only valid if they are choices that everyone should hold to at all times. In Kant's view the categorical imperative was an injunction, to be obeyed as a moral duty, regardless of an individual's impulses, to produce a humanitarian society based on reason and thus created by free will.