Introduction to Philosophy/Deontology
Deontology is a set of moral theories which place themselves opposite consequentialism. While consequentialism determines right actions from good ends, deontology asserts that the end and the means by which it is arrived upon are intrinsically linked. A good end will come about as a result of good or right means.
The most famous of deontologists is Immanuel Kant (1724 - 1804). His categorical imperative (divided into three formulations) determines a set of universal principles by which right action can be judged. The name "deontology" comes from the Greek "deon" which means "duty." Kant's goal in formulating deontology was to establish an ethical system that does not depend on anyone's subjective experience; rather, the good or evil of an action can be entirely determined by irrefutable logic. Thus, ethically correct behavior would be a duty whose truth no one could deny, just as no one can reasonably deny that two plus two makes four.
Kant's categorical imperative tells us how logic can determine whether an action is right or wrong. It revolves around the idea of the maxim that cannot be made universal without defeating itself. A classic example is the statement, "I choose to lie about my car so that I will not be punished for arriving late at work." This may work for one individual, but if everyone adopted this principle (if lying were universalized), they would cancel out the concept of promising. In a world where lying was normal behavior, no one would believe anything they were told. This is the first formulation of the categorical imperative, that any action whose maxim logically defeats itself when universalized cannot be a moral action.
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.
Another way of looking at deontology is that it is opposed teleological theories such as consequentialism. In this sense Deontology is concerned with finding the right actions that one should perform to produce the 'good', while teleology is concerned with isolating the meaning of the 'good' and then stating that a right action is one which will produce said good. Thus as well as formulating his categorial imperative Kant also states that one is acting morally when one performs one's duty to fulfill the categorical imperative.