Kantian Ethics

Kantian ethics is a deontological ethical theory first proposed by German philosopher Immanuel Kant. The theory, developed as a result of Enlightenment rationalism, is based on the view that the only intrinsically good thing is a good will; therefore an action can only be good if the maxim, or principle, behind it is duty to the moral law. Central to Kant's construction of the moral law is the categorical imperative, which acts on all people, regardless of their interests or desires. Kant formulated the categorical imperative in various ways. His principle of universalisability requires that, for an action to be permissible, it must be possible to apply it to all people without a contradiction occurring. His formula of humanity as an ends in itself requires that humans are never treated merely as a means to an end, but always also as ends in themselves. The formula of autonomy concludes that rational agents are bound to the moral law by their own will, and Kant's Kingdom of Ends formula requires that people must act as if the principles of their actions will establish a law for a hypothetical kingdom of ends. Kant also distinguished between perfect and imperfect duties. A perfect duty, such as the duty not to lie, always holds true; an imperfect duty, such as the duty to give to charity, can be made flexible and applied to certain times and places.

American philosopher Louis Pojman has cited Lutheran Pietism, political philosopher Jean-Jacques Rousseau, the contemporary debate between rationalism and empiricism, and the influence of natural law as influences on the development of Kant's ethics. Other philosophers have argued that Kant's parents and his teacher, Martin Knutzen, influenced his ethics. Those influenced by Kantian ethics include philosopher Jürgen Habermas, political philosopher John Rawls, and psychoanalyst Jacques Lacan. German philosopher G.W.F. Hegel criticised Kant for not providing specific enough detail in his moral theory to affect decision-making and for denying human nature. German philosopher Arthur Schopenhauer argued that ethics should attempt to describe how people behave and criticised Kant for being prescriptive. Michael Stocker has argued that acting out of duty can diminish other moral motivations, such as friendship; Marcia Baron has defended the theory by arguing that duty does not diminish oher motivations. The Catholic Church has criticised Kant's ethics as contradictory and challenges Kant's legalistic approach as a danger to Christian morality.