Immanuel Kant was born in 1724 in the East Prussian town of Knigsberg and lived there practically all his life. He came from a deeply pious Lutheran family, and his own religious convictions formed a significant background to his philosophy. Like Berkeley, he felt it was essential to preserve the foundations of Christian belief. Kant became Professor of Logic and Metaphysics at the University of Knigsberg in 1770 and taught there for most of his life. He was also greatly interested in science and published works on astronomy and geophysics.
His three most significant works were published later in life. The Critique of Pure Reason came out in 1781, followed in 1788 by the Critique of Practical Reason and in 1790 by the Critique of Judgment. The Critique of Pure Reason is one of the most important works in the whole of philosophy. Unfortunately it is also one of the most unreadable – Kant himself described it as dry and obscure. Kant had generally been an outgoing and friendly man but towards the end of his life his mental faculties and his sight deteriorated badly. He died a shadow of his former self, aged 80.
One of his most quoted sayings is carved on his gravestone in Knigsberg: “Two things fill my mind with ever-increasing wonder and awe, the more often and the more intensely the reflection dwells on them: the starry heavens above me and the moral law within me”. Kant believed that there are clear limits to what we can know. You could perhaps say that the mind’s “glasses” set these limits. The philosophers before Kant had discussed the really “big” questions – for instance, whether man has an immortal soul, whether there is a God, whether nature consists of tiny indivisible particles, and whether the universe is finite or infinite.
Kant believed there was no certain knowledge to be obtained on these questions. In such great philosophical questions, he thought that reason operates beyond the limits of what we humans can comprehend. At the same time there is in our nature a basic desire to pose these questions. When, for example, we ask whether the universe has always existed, we are asking about a totality of which we ourselves are a tiny part. We can therefore never completely know this totality. According to Kant there are two elements that contribute to our knowledge of the world – sensory perception and reason.
The material of our knowledge comes to us through the senses, but this material must conform to the attributes of reason. When we wonder where the world came from, however – and then discuss possible answers – reason is in a sense on hold. It has no sensory material to process, no experience to make use of, because we have never experienced the whole of the great reality of which we are a tiny part. In such weighty questions as to the nature of reality, Kant showed that there will always be two contrasting viewpoints that are equally likely or unlikely, depending on what our reason tells us.
It is just as meaningful to say that the world must have had a beginning in time as to say that it had no such beginning. Reason cannot decide between them. We can allege that the world has always existed, but can anything always have existed if there was never any beginning? So now we are forced to adopt the opposite view. Both possibilities are equally problematic. Yet it seems one of them must be right and the other wrong. Hume’s scepticism with regard to what reason and the senses can tell us forced Kant to think through many of life’s important questions again.
He was especially interested in ethics. For Hume it was neither our reason nor our experience that determined the difference between right and wrong. It was simply our sentiments. This was too tenuous a basis for Kant, who had always felt that the difference between right and wrong was a matter of reason, not sentiment. In this he agreed with the rationalists, who said the ability to distinguish between right and wrong is inherent in human reason. Everybody knows what is right or wrong, not because we have learned it but because it is born in the mind.
According to Kant, everybody has “practical reason”, that is, the intelligence that gives us the capacity to discern what is right or wrong in every case. The ability to tell right from wrong is as innate as all the other attributes of reason. Just as we are all intelligent beings, for example, perceiving everything as having a causal relation, we all have access to the same universal moral law. Kant formulates the moral law as a categorical imperative. By this he means that the moral law is “categorical”, or that it applies to all situations.
It is, moreover, “imperative”, which means it is commanding and therefore absolutely authoritative. He formulates this “categorical imperative” in several ways. First he says: “Act only on that maxim through which you can at the same time will that it should become a universal law”. So when you do something, you must make sure you want everybody else to do the same if they are in the same situation. Another way Kant formulated the “categorical imperative” was: “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 always at the same time as an end”.
For Kant, the law of morals is just as absolute and just as universal as the law of causality. That cannot be proved by reason either, but it is nevertheless absolute and unalterable. When Kant describes the law of morals, he is describing the human conscience. We cannot prove what our conscience tells us, but we know it nonetheless. Sometimes you might only be kind and helpful to others because you know it pays off. It could be a way of becoming popular. But if this is your only motive you are not acting out of respect for moral law.
You might be acting in accordance with moral law – and that could be fair enough – but if it is to be a moral action, you must have conquered yourself. Only when you do something purely out of duty can it be called a moral action. Kant’s ethics is therefore sometimes called duty ethics. Kant also advocated the establishment of a “league of nations”. In his treatise Perpetual Peace, he wrote that all countries should unite in order to assure peaceful coexistence between nations.
He believed that man’s “practical reason” would force the nations to emerge from the wild state of nature which creates wars, and make a contract to keep the peace. Kant recognised that this would take time to achieve but he saw it as our duty to work for the universal and lasting securing of peace. About 125 years after the appearance of Kant’s treatise in 1795, the League of Nations was founded, after the First World War. After the Second World War it was replaced by the United Nations.
