Immanuel Kant was born on April 22, 1724, in Königsberg, Prussia (Now Kaliningrad, Russia). He was of Scottish descent and had a Pietist upbringing and education. (Pietism is a form of Protestantism similar to Methodism, i.e. very conservative.) He went to the University of Königsberg, where he received his PhD. He taught as a privatdozent, which is a private teacher or tutor, paid by his students. This meant a poor life, boardinghouses, and bachelorhood.

He began with an interest in science -- physics, astronomy, geology, biology. In fact, he introduced the nebular hypothesis, suggesting that originally, swirling gases condensed into the sun and the planets -- basically, what we understand to be the reality today. He also reintroduces Lucretius’s idea of evolution of plant and animal life.

In 1781, he published the Critique of Pure Reason. Critique means a critical or careful analysis, and pure reason means reason which leads to knowledge that doesn’t require experiential proof, what is also called a priori (before-hand) knowledge.

He said he had been “awakened from his dogmatic slumbers” by reading Hume. This is frequently misunderstood to mean that he was outraged. Actually, he said that he had been dogmatically accepting of the traditional ideas about reason. Hume enlightened him! However, it is also true that Hume challenged him, in a sense, to rescue such concepts as cause and effect, which Kant felt were essential to the existence of science. He took as his life's task to saving of the universe from Hume's pervasive skepticism.

First, he makes a distinction between a posteriori and a priori knowledge:

It is a question worth investigating, whether there exists any knowledge independent of experience and all sense impressions. Such knowledge is called a priori and is distinguished from a posteriori knowledge which has its sources in experience. That there is genuine a priori knowledge, that we can advance independent of all experience, is shown by the brilliant example of mathematics....

Although all our knowledge begins with experience, it does not follow that it arises entirely from experience. For it is quite possible that our empirical knowledge is a compound of that which we receive through impressions and that which our own faculty of knowing (incited by impressions) supplies from itself--a supplement to impressions which we do not distinguish from that raw material (i.e. impressions) until long practice has roused our attention and rendered us capable of separating one from the other.

What then are these a priori faculties of our minds? The first stage of mind's operation on experience is the transcendental aesthetic, which states that all sense experience is synthesized "through" the concepts of time and space.

Space does not represent any property of things in themselves, nor does it represent them in their relation to one another.... Space is nothing but the form of all appearances of outer sense. It is the subjective condition of sensibility under which alone outer perception is possible for us.

Since the capacity to be affected by objects must precede all perception of these objects, it can readily be understood how the form of all appearances (i.e., space) can be given prior to all perceptions, and so exist in the mind a priori; and how, as a pure intuition, in which all objects must be determined, it can contain, prior to all experience, principles which determine the relations of these objects. It is, therefore, solely from the human standpoint that we can speak of space, of extended things. If we depart from the subjective, the representation of space stands for nothing whatsoever.

Time is a purely subjective condition of our human perception, and, in itself, apart from the subject, is nothing.... What we are maintaining is the empirical reality of time, its objective validity of all objects which allow of ever being given to our senses. Since our perception is always sensible (i.e., by the senses), no object can ever be given to us in experience which does not conform to the condition of time. On the other hand, we deny to time any claim to absolute reality; that is to say, we deny that it belongs to things absolutely, as their condition or property independently of any reference to the form of our perception. Properties that belong to things in themselves can never be given to us through the senses. This, then, is what constitutes the ideality of time.

So time and space are necessary to perception, even though they themselves cannot be perceived apart from the events "in" them. The next step is the transcendental analytic, which says that the mind applies certain categories of thought to ideas. Without these categories, Kant says, we would not be able to think at all, and Hume couldn't have come up with his arguments. Hume, for example, felt that cause and effect were not objectively real; Kant says right! -- they are a priori, in the mind:

1. Quantity: unity, plurality, totality.

2. Quality: reality, negation, limitation.

3. Relation: substance and accidents, cause and effect, reciprocity between active and passive.

4. Modality: possible-impossible, existence-nonexistence, necessity-contingency.

Finally comes the transcendental dialectic. Kant believed that the mind seeks complete knowledge. But it is limited to dealing with phenomena, appearances, only. It can't reach to noumena, the thing-in-itself. Phenomena are all you have, but they are not real; noumena are real, but you can't have them. So, to discover that real world, we try to construct it. Unfortunately, we err by trying to use the categories (logic), "designed" for phenomena, on the ultimate reality! So we end up with contradictions that are irreconcilable. Regarding cause and effect and free will:

If, however, we may legitimately take an object in two senses, namely, as phenomena and as thing-in-itself; and if the principle of causality applies to things only as phenomena and not as noumena, then we can, without any contradiction, think one and the same thing when phenomenal as necessarily conforming to the principle of causality and so far not free, and yet, in itself not subject to that principle and therefore free.

Suppose morality necessarily presupposed freedom of the will while speculative reason had proved that such freedom cannot even be thought. In such case freedom, and with it morality, would have to make room for the mechanical interpretation of nature. But our critique has revealed our inevitable ignorance of things-in-themselves, has limited our knowledge to mere phenomena. So, as morality requires only that freedom should not entail a contradiction, there is no reason why freedom would be denied to will, considered as a thing-in-itself, merely because it must be denied to it as a phenomenon.

Ultimately, Kant found that the existence of God, the soul, and ultimate reality is not something you can prove, because proof is based on phenomena and the categories. Instead, they are heuristic, that is, we believe in these things because they are useful to us! In saving science and religion from Hume, he proved that they had to be taken on faith! Scholars and churchmen on all sides of the issues criticized the Critique, which ironically guaranteed its success. Kant had no censorship problems to worry about at the time, because Frederick the Great -- a brilliant man himself -- ruled Prussia at that time. Unfortunately for Kant and many others, he died in 1786.

(A note on Frederick the Great: The King of Prussia, including much of Germany as well, he was, besides a consummate leader and politician, an accomplished philosopher and a passionate amateur musician. He corresponded with Voltaire and Rousseau, and Bach wrote “A Musical Offering” for him, based on a melody the King had challenged him with. He wrote a number of books, including A History of My Times and The Anti-Machiavelli)

In 1788, Kant wrote the Critique of Practical Reason. Practical reason refers to the making of moral decisions. In this book, he argues that everyone has a conscience, a moral law within their souls, not unlike the categories of the Critique of Pure Reason. This moral law he calls the Categorical Imperative, which is phrased two ways. The first is a variation on the Golden Rule: Whatever you do, consider what kind of world this would be if everybody did the same. The other is a little deeper: Treat people (including oneself) only as ends, never as means to an end. Never use them, we would say today.

In order to have morality, Kant believed we needed free will. If you can’t make choices, how could you be responsible? If you aren’t responsible for anything you do, like an animal or a robot, then what you do is neither bad nor good! Also, he felt we needed the idea of immortality: Since justice rarely happens within a lifetime, we need life after death to take care of that. And, in order for eternal life to exist, or free will, or good and bad at all, we need to believe in God.

Notice that he doesn’t say that, first God exists, therefore.... He is actually saying that, although we can never prove the existence of God (or immortality, or free will, or good and bad), we must act as if he (and they) existed. Religious thinkers of the time did not care for this way of thinking at all!

Kant wrote a good deal more. In 1790, he wrote the Critique of Judgement, regarding judgements of beauty. He notes that our sense of beauty is based on feeling, not reason. We seem to “see” the harmony, the power, the miraculous in some things. It is as if God so arranged things!

In 1793, when he was 69 years old, Religion Within the Limits of Reason Alone came out. Here he argues (unlike Hobbes and unlike Rousseau) that we are born with the potential for both good and bad. He does acknowledge, though, that a great deal of evil comes out of civilization, rather than our primitive nature. In fact, a lot of what we now consider bad was probably originally necessary for survival in primitive conditions!

He also said that, although there is an inborn moral sense, it must be developed by moral instruction. For this reason, he believes that religion is necessary -- although he also points out that religion shouldn’t be dogmatic, and that beliefs such as original sin, the divinity of Christ, and the efficacy of prayer are mere superstitions.

In 1795, he wrote On Perpetual Peace, outlining the basis for international law. In 1798, he came out with , arguing for the importance of academic freedom. He died February 12, 1804, after a long illness, and was buried ceremoniously in Königsberg Castle. Over his grave is written

The starry heavens above me;

The moral law within me.

The great modern historian of psychology, Dan Robinson, once said that today nearly every psychologist is either a Humean or a Kantian. Humeans see their science as the statistical analysis of a collection of experiences. All we can ever know is probabilities based on what happened in the past. Kantians see their science as more firmly based, in a sense, in the structure of the mind. And yet they, too, can permit themselves little certainty. Humeans can be found among most experimentalist, including the behaviorists. Kantians are more likely to be found among cognitivists and psychoanalysts. There are, as we shall see, alternatives. But they remain very much in the minority.

© Copyright 1999, C. George Boeree