One of the most influential figures on Western philosophical thought was Immanuel Kant (1724-1804), a German philosopher active during the 18th Century. Kant’s contributions to the fields of metaphysics, epistemology, ethics, and aesthetics (four of the main branches of philosophy) have had a profound impact on almost every philosophical movement that followed him. Throughout his works, Kant argued that
- the human mind creates the structure of human experience,
- that reason is the source of morality,
- that aesthetics arises from a faculty of disinterested judgment,
- that space and time are forms of human sensibility,
- and that the world as it is “in-itself” is independent of humanity’s concepts of it.
In terms of politics, Kant was one of the earliest proponents of the idea that political peace and stability could be achieved through international cooperation and worldwide democracy and believed that such a situation would be the eventual outcome of universal history.
One of the main areas in which Immanuel Kant left his mark on was in the realm of Deontological Ethics. Derived from the word deon (“duty” in Greek), this ethical theory holds that there is an innate aspect to a given moral rule that makes it either good or bad. Thus, Kantian/Deontological ethical theory is based on established definitions of morality. The main aspect of Kant’s theory was the Categorical Imperative.
Immanuel Kant defined an imperative as any proposition that declares a certain action (or inaction) to be necessary. A hypothetical imperative would compel action in a given circumstance (if I wish to satisfy my thirst, then I must drink something). A categorical imperative would denote an absolute, unconditional requirement that exerts its authority in all circumstances, both required and justified as an end in itself.
He argued that the “highest good” must be both intrinsically good (good “in itself”), and good without qualification (when the addition of that thing never makes a situation ethically worse). He concluded that there is only one thing that is truly good: a goodwill chosen out of a feeling of moral duty. From this concept of duty, Kant derived what he called a categorical imperative, a principle that is intrinsically valid (good in and of itself), and that must be obeyed in all situations and circumstances if our behavior is to observe moral laws. He considered it an unconditional obligation, regardless of our will or desires, and regardless of any consequences which might arise from the action. He also believed that if an action is not done with the motive of duty, then it is without moral value and therefore meaningless.
Kant developed his moral philosophy in three works: “Groundwork of the Metaphysic of Morals” (1785), “Critique of Practical Reason” (1788) and “Metaphysics of Morals” (1797) and formulated it in three different ways :
- Act only in such a way that you would want your actions to become a universal law, applicable to everyone in a similar situation.
- Act in such a way that you always treat humanity (whether oneself or other), as both the means of an action, but also as an end.
- Act as though you were a law-making member (and also the king) of a hypothetical “kingdom of ends”, and therefore only in such a way that would harmonize with such a kingdom if those laws were binding on all others.
The idea of Deontological Ethics as proposed by Immanuel Kant is not without its share of critics, in particular, proponents of Libertarian philosophy, as well as the idea of Utilitarianism are opposed to the theory. The Libertarian philosopher Robert Nozick points out that Deontology forbids some acts that maximize welfare overall. The example used is that of a trolley hurtling towards five innocent and immobile people at the end of a track, where the only way to stop the trolley and save the five is to throw one innocent bystander in front of the trolley. The Principle of Permissible Harm in Deontology rules out deliberately throwing a person in front of the trolley, but the consequence of that is that five innocent bystanders die (which also contravenes the Principle of Permissible Harm).
Proponents of Utilitarianism such as Jeremy Bentham have criticized Deontology on the grounds that it a version of popular morality, and that the objective and unchanging principles that deontologists attribute to natural law or universal reason are really just a matter of subjective opinion. John Stuart Mill argued that deontologists usually fail to specify which principles should take priority when rights and duties conflict, so that Deontology cannot offer complete moral guidance. Mill also criticized Kant’s claims for his Categorical Imperative, arguing that it is really just another way of saying that the ends justify the means, which is essentially a consequentialist argument.