Immanuel Kant and the Categorical Imperative


NOTE: This is a Christian website and presents a Christian interpretation of Kant

For a preliminary discussion of Kant's philosophy click here

Deontological Ethics - The claim that an action is right or wrong independent of the consequences (the end does not justify the means).
Teleological Ethics - The claim that an action is right or wrong on the basis of the consequences/outcome - see Natural Law (the means is justified by the end).

Immanuel Kant sought to draw together a number of paradoxes (what he called antimonies) in his philosophical and ethical explorations. Key to Kant's ethics is the concept of freedom (for further discussion see Determinism and Freewill). However, this notion is actually philosophically grounded in his epistemology and what is known as the phenomenon (things as they appear to us), and the noumenon (things as they really are). In this respect Kant followed Plato who divided reality into what is perceived to be the case and what is actually the case (objective reality), in his theory of the Forms. Although Kant doubted the possibility of the mind verifying its knowledge of reality he was actually more than an Idealist [1].

Immanuel Kant is a deontologist which means he believed in a sense of 'duty' which one should follow on all occasions. In terms of ethics he believed it was important to find out what these duties were and provide rational grounds/reasons as to why we must obey them. To do this Kant split reason into 'theoretical reason' (which covered maths and logic) and 'practical reason' (which he believed was superior as it involved a struggle to follow and led to people becoming 'moral/good people'). Practical reason is also grounded in a sense of 'ought'. In others words, by a careful consideration and weighing of the 'facts' people will become aware of what their duty is in each case and  do it. Thus 'ought' implies can. We will never have a sense of 'ought' about things we cannot (or should not) do.

Kant was careful to ground practical reason in rationality to make it clear that to be a moral person was not easy. He believed that true morality was developed in the face of a real choice between right and wrong ('autonomy of the will'). In the light of this he advocated freedom as one of three fundamental truths of the universe (the others being God and Immortality). Without freedom there was no choice. Without choice there was no struggle. Without struggle there is no genuine morality (as feelings and desires are not a reliable guide on which to base moral judgments. If one performed a moral act based on feelings and desires this would be by accident. The necessity for freedom in his logic led Kant to consider that although moral statements were a priori (independent of existence) they were also synthetic (able to be verified by experience). By doing this he avoided making morality a non-choice event and allowed the human subject to soberly weigh up and consider genuine moral choices. Without this he would have been facing a rational version of the Euthyphro Dilemma. Kant also believed it was important to consider duty rather than desires (wants), and motive rather than consequences. Thus he made morality doing what comes naturally but also resisting what comes naturally (E.g. Only acting for pleasurable outcomes).

Kant's most well known contribution to ethical discussion is the Categorical Imperative. These are ends in themselves and the basis for all action (in contrast to Hypothetical Imperatives which are a means to an end (E.g. If you go on a diet then you will lose weight) and do not have to be followed (E.g. I do not have to go on a diet)). In religious terms a Hypothetical Imperative could be 'If you obey God then you will get to heaven' but a Categorical Imperative would be 'Obey God! It is your duty' (although it is conceivable that all religious Categorical Imperatives are in fact Hypothetical Imperatives but this would depend on one's presuppositions)'. Thus, according to Kant, one does not question Categorical Imperatives as they are fundamental truths of the universe.

In 'Groundwork of the Metaphysics of Morals' (1785) Kant offers three progressive versions of the Categorical Imperative on which all moral commands are based:

1. 'Act as if the maxim of your action was to become through your will a universal law of nature.' 

In Christianity this could be expressed as 'Treat others as you want them to treat you.' (Matthew 7:12)). In other words, would we be happy for others to act in the same way we do?

2. 'Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but at the same time as an end.' 

This means that humans are the most important factor in any ethical decision making. Human suffering is never justified as a means to any end.

3. 'So act as if you were through your maxims a law-making member of a kingdom of ends'

We should always keep in mind the rights of others. No-one should ever become a pawn in our 'game of life'. 

In contrast to traditional Christian theology Kant believed that human nature was fundamentally good (innate sense of 'ought'/duty) and thus could reason correct moral choices. This 'goodness' was not trained (E.g. see Aristotle and the Law of the Mean) but was 'good through its willing alone'. Christian theology has traditionally taught that humans are innately corrupt and cannot make right moral choices which are not tainted by selfish desire (see Conscience and Egoism/Hedonism). Kant taught that people only become corrupt if they refused to follow the Categorical Imperative. However, the problem here becomes how to explain moral regeneration (E.g. a criminal 'mending their ways')? If humans are corrupted by ignoring the Categorical Imperative then what is the 'spark' that ignites the flame of morality? It was here that Kant also turned to God as the necessary source of human regeneration (as God was also for Kant the necessary judge of humanity if the universe was to be seen as being moral (see Moral Argument for the Existence of God)).

Kant's maxim of the Kingdom of Ends is an attractive moral position and one that seeks to respect each person's individuality in a way that Utilitarianism, for example, may wish to, but does not seem able to. However, there are worrying aspects of Kant's ethical theory that also need to be addressed. For instance, the sense that motives rather than consequences are only important seems to lead to questionable outcomes. For instance, should an unqualified surgeon, who has attempted an emergency heart bypass operation where the patient has died, not be accountable for their actions even though they acted according to the Categorical Imperative? There seems to be an intimate relationship between act and consequence which Kant probably bypasses through fear of being deterministic. If Kant allowed that acts were right or wrong in themselves then he would have to allow that they were wrong outside the scope of the Categorical Imperative. But this would mean humans would not struggle with the rational choice of doing, or not doing, these acts and thus, according to Kant, would not be making an autonomous moral choice. On the other hand, if there is to be accountability for actions performed then this may be necessary. 

Kant's insistence that to be moral one needs to be autonomous (free) is a debatable point as is how far humans are actually free under Kant' scheme. One could have complete determinism yet be a moral person. It really depends on whether one chooses to link morality with human flourishing. In other words, is morality about making the right choices or about being the right person? There is also an interesting relationship between human autonomy and the Categorical Imperative. If there are a priori duties which humans should perform then we have to question whether we are truly free agents as Kant would desire us to be. If 'ought' implies can then according to Kant it also implies should. Am I free to make a decision otherwise without being judged by the 'ought'? Am I only free in so far as I relate to the 'ought' or can I choose to ignore the Categorical Imperative and still live a fulfilled life? If not, then I am not truly free.

Furthermore, the a priori 'duties' also raise questions as to the grounds of morality. If they are human Imperatives (grounded in human reason alone) then they are merely subjective and are not Categorical but Hypothetical Imperatives. If they are Categorical in some Ultimate sense then this raises the question of a 'Law giver' and ultimately gives rise to the question of God (which may be necessary for Kant yet again).


Ethics for Beginners by D.Robinson and C.Garratt

'The Puzzle of Ethics' by Peter Vardy & Paul Grosch

The Oxford Companion to Philosophy by T.Honderich (Ed.)



[1] Idealism is the belief that as we cannot verify our knowledge of reality all we are left with are our thoughts. This means that the only certain world is one that takes place in our mind. Ultimately, this means that the only real world is in our mind. Kant is not an Idealist as he believed the mind was able to gain knowledge of an objective realm which existed outside the mind.


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Department of Communication, Seton Hall University