A moral imperative is a principle originating inside a person's mind that compels that person to act. It is a kind of categorical imperative, as defined by Immanuel Kant. Kant took the imperative to be a dictate of pure reason, in its practical aspect. Not following the moral law was seen to be self-defeating and thus contrary to reason. Later thinkers took the imperative to originate in conscience, as the divine voice speaking through the human spirit. The dictates of conscience are simply right and often resist further justification. Looked at another way, the experience of conscience is the basic experience of encountering the right.