Introduction to Philosophy/Deontology
The term "deontology" comes from the Greek "deon" which means "duty." According to the philosophy of deontology rightness or wrongness of an action is to be determined by the act itself, and not by its consequence.
Immanuel Kant is the most known deontologist. He distinguished two kinds of imperatives (meaning commands): hypothetical imperatives and categorical imperatives. Hypothetical imperatives are commands which is conditional on one's desire. For example if one wants to get highest marks in examination he must study hard. In this example the person has to study hard only to achieve goal which is highest marks in examination. If the person does not have any goal, then hypothetical imperative doesn't work. On the other hand, categorical imperatives are commands which one person is bound to follow irrespective of goal. These imperatives are categorical in the sense that we have to follow this imperatives regardless of our desire. Categorical imperatives can be derived by reason and order of the divine entity. We have to follow these imperatives just because it is our moral duty, even if we do not want to follow these.
Kant argues that categorical imperatives can be expressed in three different formulations. The first formulation of the categorical imperative states: “Act only according to that maxim through which you can at the same time will that it become a universal law”. By this, Kant meant that the maxim (meaning rule) should be universal in the sense that it is a rule that could bind all rational beings. The second formulation as stated by Kant is: "Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end". This means that we are never allowed to merely use people, people must be respected as ends in themselves. Kant explains the third formulation as, “act in accordance with the maxims of a member giving universal laws for a merely possible kingdom of ends” Kant states that one is acting morally when one performs one's duty to fulfill the categorical imperative.
John Rawls is a deontologist as well. His book A Theory of Justice establishes that a system of wealth redistribution ought to be created such that it abides by a specific set of moral rules.
Deontology is opposed to teleological theories where rightness and wrongness of an action is determined by rightness and strongness of consequence of the action.
