Immanuel Kant (1724-1804) has been looked upon as one of the greatest of modern philosophers. Throughout his life, he lived in or near Konigsberg, in East Prussia. His outer life was academic, and it seemed even uneventful. It was during the course of his life that Russia occupied East Prussia; but this great event had no impact on his life. He also witnessed French Revolution and the earlier part of Napoleon's career, but even this great event did not seem to have played any great role in his life. Although he studied Leibnitz’s philosophy, he was led to Rousseau and Hume. As far as Hume is concerned, Kant himself had confessed that it was his criticism of the concept of causality that awakened him (Kant) from his dogmatic slumbers.
Kant was a man of regular habits; it is said that people used to set their watches by him as he passed their doors, except on one occasion when his time-table was disrupted for several days. It is interesting to note that this disruption was caused by his intense reading of Rousseau's great book "Emile". Kant has commented that he was required to read Rousseau's books several times because, at the first reading, the beauty of the style prevented him from noticing the matter.
Kant was brought up as a pietist, but he was a Liberal both in politics and theology. He sympathised with the French revolution until the Reign of Terror, and was a believer in democracy. In his philosophy, he gave great importance to the demands of morality rather than to the cold dictates of theoretical reason. According to Kant, every man should be regarded as an end in himself. This doctrine is very well embedded in the modern doctrine of the Rights of Man. He was such a great lover of freedom that he stated that “there can be nothing more dreadful than that the actions of a man should be subject to the will of another."
It is also interesting to note that Kant's early works were more concerned with science than with philosophy. He wrote at one stage on the theory of earthquakes. He has also written a treatise on winds; and Physical geography was a subject in which he took great interest. In 1755, he wrote his most important scientific book "General Natural History and Theory of Heavens". He also wrote a treatise on the sublime and the beautiful. He declared that night is sublime, day is beautiful; the sea is sublime, the land is beautiful; man is sublime, woman is beautiful; and so on. It has been remarked that as he never married, he kept the habits of his studious youth to old age.
Kant's vigour and freshness of mind in old age are shown by his treatise on Perpetual Peace (1795). In this work, he advocates a federation of free States, bound together by a covenant forbidding war.
Kant's most important book in the field of philosophy is "The Critique of Pure Reason", the first edition of which came out in 1781. It is the theoretical function of the faculty of reason that constitutes the topic of "The Critique of Pure Reason", while the practical function, that of "The Critique of (Pure) Practical Reason". In the Critique of Pure Reason, Kant speaks of three cognitive faculties: sensibility, understanding and reason. According to Kant, sensibility is nothing but the capacity of the human mind to receive impressions in space and time. Understanding contributes, a priori, some pure concepts which determine the very forms of the different judgments that we make. These pure concepts enable us to synthesise the manifold of sense according to rules, so that we can have objective experience in the true sense. The application of the pure concepts to the manifold of sense requires some interpretation of these concepts in terms of the form of the sensibility, namely, space and time.
According to Kant, space and time are not concepts, but they are forms of intuition. As far as concepts are concerned, they are categories and there are illustrations to these categories. Space and time are not categories since there are no illustrations of time and space. According to Kant, there are twelve categories, and they are divided into four sets of three:
These concepts are the part of our mental constitution and they are applicable to whatever we experience.
An important part of Kant's philosophy is that while, the concepts of categories and intuitions of space and time can be applied to things that are experienced, they cannot be applied to things-in-themselves. He pointed out that if you tried to apply categories or intuitions to things-in- themselves, we are led to self-contradictions or to antinomies (It may be recalled that an antinomy is a proposition from which two mutually contradictory propositions can be derived, and yet both of them are necessary derivations).
Apart from sensibility and understanding, Kant maintains that reason performs the function of developing regulative principles, in terms of which we systematise. Ideas of reason, according to Kant, are regulative;
they are regulative of the operations of understanding. There are three ideas of reason: Soul, World and God. These ideas of reason set a goal for understanding, and the categories of understanding function within the regulative ideas of the soul, world and God.
Is there any way by which we can come to know things-in-themselves?
Here we come to Kant's conception of pure practical reason. Kant's conception of rationality in its practical aspects is that rationality consists in adopting the right means to the end we have, and in having the right ends. It is in exercising practical reason that we are able to lift ourselves from the realm of the world that we experience by the help of categories of understanding, and begin to experience things-in-themselves and "the moral will". According to Kant, moral will is free from the conditions of the world of experience, and therefore, it is not subject of conditional imperatives. According to Kant, moral will is the Categorical Imperative. It is in the exercise of the categorical imperative that we are able to understand and experience what lies beyond our ordinary category of experience. It is in the exercise of the categorical imperative that we come to experience the immortality of the individual soul. It is, again, in the exercise of the categorical imperative that we come to experience freedom. Still again, it is in the exercise of the categorical imperative that we find God as the foundation of the totality of our existence.
The categorical imperative has also been illustrated as "Duty for duty's sake". According to Kant, the individual normally acts under conditions in order to gain certain results. But so long as he seeks results, he is bound to conditions and results. When he exercises moral will, he goes beyond conditions and seeking for results. He becomes aware of Goodwill, which is unconditional and which acts simply because it is good and not because it seeks any specific results. It is in the exercise of the moral will or goodwill that the individual is liberated from the chain of causes and effects, and performs an action simply because that action is good in itself, simply because it is right in itself, simply because it is an intrinsic end itself. According to Kant, duty is to be performed because it is a duty, because it is good in itself, because it is an end in itself. It is only when an action is done for its own sake, when an action is good in itself that in performing that action one experiences true
freedom, and in the exercise of freedom, one also experiences the immortality of the soul.
Kant has provided three alternative formulas of judging whether a categorical imperative is really categorical. According to the first formula, a categorical imperative can be expressed as follows: Act according to a maxim by which you can at the same time will that it shall become a general law. According to the second formula, the categorical imperative can be expressed as under: Act in such a way that others are regarded not merely as means but as ends in themselves. According to the third formula, the categorical imperative can be expressed as follows: Act as the member of the realm of ends.
Kant has remained important in the history of Western Philosophy both for his theory of categories of reason and for his theory of categorical imperative. Both these subjects are still being discussed by philosophers, Western and Eastern.