This approach to ethics was most influentially formulated by the philosopher Immanuel Kant. In contrast to consequentialist theories like utilitarianism, which hold that an action is morally right if it produces the best or happiness for the most people, deontological ethics argue that certain actions are intrinsically right or wrong, regardless of their outcomes.
For instance, a deontologist might argue that lying is always wrong, even if it results in a better outcome for someone because honesty is seen as a duty that should always be upheld.
One of the central concepts in Kant’s deontological ethics is the idea of the “categorical imperative.” This is a principle that we must follow regardless of our desires or personal goals. Kant proposes several formulations of this imperative, including: “Act only according to that maxim whereby you can at the same time will that it should become a universal law,” and “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.”
In short, deontology posits that morality is bound by rules and duties and that the rightness or wrongness of an action is determined by its adherence to these rules, rather than its consequences.