The Categorical Imperative was devised by Immanuel Kant to provide a set of requirements a maxim (or motivation) must pass in order for the action to be considered a moral obligation. When a Categorical Imperative is established it becomes one’s moral duty to carry out the action under any circumstances. When carrying out this action, the individual’s primary motive should always be duty according to Kant; this is because we can decipher what our duty is by using our reason. Human’s ability to reason is what deciphers us from animals and so, logically, must be part of being a moral agent. Reason is objective and universal for humanity and so is a reliable and reasonable basis for a moral theory.
The Categorical Imperative is determined by referring to three formulations. The first formulation, namely the Formula of the Law of Nature, insists that we should act ‘only according to that maxim’ which could be universalised. This means that we must be able to universalise a principle without contradiction. If this is not possible, we can logically assume that the act is immoral as it is counter to reason. If a rule is not universalisable then others will not be free to act from the same moral principles, and Kant strongly believed that autonomy and freedom were essential to being a moral agent. The second formulation (The Formula of End in Itself) ensures that you never treat others or oneself ‘merely as a means but always as an end’. To use someone merely as a means to some other end is to exploit their rationality, and we should value everyone as rational beings. Lastly, the Formula of a Kingdom of Ends asks for us to ‘act as if a legislating member in the universal Kingdom of Ends’. The Kingdom of Ends is a world in which everyone acts from categorical imperatives, and although we may not live in this world, we must act as if we are. According to this formula we must act on the assumption that everyone will follow the rules you make through your actions. If the intended action passes each of the formulations it is a categorical imperative and thus is not only right, but a moral obligation.