Kant in 60 Minutes

Great Thinkers in 60 Minutes

Walther Ziegler

• Publisher: Books on Demand
• Year: 2016
• Print ISBN:
  9783741226373
• eBook ISBN:
  9783741230196
• Edition: 1
• Topic: Philosophy
• Subtopic: Philosophy History & Theory

Immanuel Kant is thought to be perhaps the greatest of all philosophers. And Kant did make, in the 18th Century, two great discoveries which engage us still today. Firstly, he founded the globally acknowledged 'categorical imperative' in moral philosophy; secondly, he became the first philosopher to succeed in answering that question as old as humanity of how knowledge arises in our brains. In his main work, the 1000-page "Critique of Pure Reason", Kant analysed the working of Man's thinking apparatus. He posed the critical question: what can a human being know with certainty and what can he not? His famous answer: Our reason can provide true and certain knowledge only of that which we have already perceived through our five senses (i.e. seen, heard, smelt, tasted, or touched). For this reason one cannot prove the existence of God, say, or really have "knowledge" of Him, because He is bodiless and imperceptible. Kant thus gave researchers, for the first time, a set of logical tools which was sensationally simple and yet quite perfect, and that still remains valid today and makes all scientific results achieved worldwide mutually comparable. Every theory, however good, had thenceforth to be proven in terms of actual sense-perceptions, for example through repeatable experiments. In his second main work, the Critique of Practical Reason, he tackled the equally ambitious question: 'what is the right way for a human being to act?' Is there a single valid standard for morally right action? Here too Kant provided a spectacular solution that is still passionately debated, globally, today. The book "Kant in 60 Minutes" explains both these major works of Kant's in a lively way, using over eighty key passages from the works themselves and many examples. The final chapter on "what use Kant's discovery is for us today" shows the enormous importance of his ideas for our personal lives and our society. The book forms part of the popular series "Great Thinkers in 60 Minutes".

Kant’s Central Idea

What Can I Know?

The Critique of Pure Reason

Kant once stated in one of his philosophical lectures that there are, in philosophy, really only four questions of any true importance: ‘what can I know?’; ‘what ought I to do?’; ‘what may I hope?’; and ‘what is Man?’ He engaged above all with the first two of these four questions.

The fundamental question of what a human being can know is investigated by Kant in his mighty thousand-page masterwork, the Critique of Pure Reason. As in the case of ‘intuition’, we should take note of a change in the meaning of the word ‘critique’ between Kant’s day and ours. Today, ‘critique’ implies a negative judgment; but Kant uses it rather in the original sense of the Greek word it comes from: ‘krinein’, which means ‘investigate’ or ‘examine’. He wants to investigate what pure reason can and cannot do. He compares this critical examination to a court trial at which reason is at the same time prosecutor and accused, inasmuch as it is (self-)compelled to examine, (self-)critically, its own capacities. Kant believed such a rigorous ‘trial’ to be, after two thousand years of philosophy, long overdue; the philosophers’ centuries-old discussion about truth was threatening, he thought, to sink into contradictions and chaos and the age itself now demanded that

It is clear from these last remarks just how vast an undertaking Kant envisaged. He is not concerned with any new philosophical or scientific theory but with something much more fundamental. His intent is to examine just what, where human reason is applied correctly, can, in theory, be known and what cannot possibly be known.

The source of these errors is, Kant contends, a lack of knowledge of the apparatus itself of human thinking. Too often in the past, and still today, this apparatus of thinking is applied in the wrong way. Kant wants, as he stresses over and over again, to establish ‘once and for all’ – that is to say, for all times past and future – a foundation for any science really worthy of the name ‘science’. He wants to clarify just what we are really talking about when we talk about ‘scientific knowledge’.

The Dispute between Rationalists and Empiricists

In Kant’s time there existed two major currents in philosophical thought: rationalism and empiricism. These two schools of thought were deeply at odds, with the rationalists condemning the empiricists as naive and the empiricists the rationalists as narrow-minded dogmatists.

The rationalists drew their name from the Latin word ratio, which does in fact mean simply ‘reason’. And it was indeed on reason alone that these philosophers built all their accounts of truth and the world. It was only with the aid of reason, they argued – that is to say, through rational contemplation and the process of logical conclusion – that true insights were arrived at. It was just such a decisive and even exclusive role in the discovery of truth that was assigned to reason by the famous dictum of the French rationalist, Descartes: “I think, therefore I am.”

For these advocates of reason, then, nothing else that human beings might base their ideas about the world on – for example, what we perceive through our five senses – is really sufficient to arrive at truth. Take, for example, the rising of the sun. To believe that the sun rises merely because one sees it do so every morning might well be to fall victim to an optical illusion. Looked at in rationalist terms – that is to say, purely logically – the proposition ‘the sun rises’ is quite false. In these terms it would be more correct to say that in the morning the earth turns toward the sun and in the evening away from it. It might also sometimes be erroneous to claim that someone is big simply because he appears to cut an imposing figure. In comparison to others he may be small. The decisive thing, then – so it might be argued – is not what we perceive about a thing or a person through our senses but rather the rational idea ‘relation’ and the logical inferences that follow from it. Ratio – reason – alone, being the competent faculty for logical comparisons, can decide whether someone is big or small, or whether it is the sun that ‘rises’ or the earth that ‘turns’ toward the sun. True statements, the rationalists contended, were only possible where reason applied the logic of comparative or causal thought.

The rationalists, then, wanted to explain the whole world through logical deductions alone. In this way, they also claimed knowledge of such metaphysical truths as the existence of God. They reasoned, for example, as follows: if the movements of the world or of nature consist in a long sequence of causes and effects, then it follows logically that there must have been a First Cause, or ‘Prime Mover’, that set everything in motion without itself being set in motion by anything else, i.e. stands outside of the chain of natural cause and effect. It was nothing unusual for the rationalists – who included, besides Descartes, such still well-known figures as Spinoza and Leibniz – to offer such ‘proofs of God’s existence’ on purely logical grounds.

Empiricism claimed the exact opposite to this: namely, that it is not thinking but rather experience – that is to say, the perception of the world through our five senses – that is the only reliable source of truth. The empiricists took their name from the Latin word ‘empiricus’: ‘following experience’. They were fascinated by the natural sciences, just beginning to flourish at this time, and their experiments. They shared the sentiment of Goethe’s Faust that ‘all theory is grey’ and that living knowledge is acquired by looking at things with one’s own eyes and holding only to the concretely perceptible. The spirit of bold experimentation even cost one of the fathers of the empiricist current, Francis Bacon, his life. It is said that he died of pneumonia while trying to establish whether snow could be used to keep a dead fowl fresh.

Such a demise, however, only brought Bacon greater honour in the eyes of the empiricists. Their motto was: knowledge of Nature and its laws is to be gathered only from data acquired through the physical senses. They envisaged human reason as a vessel which is, at each man’s birth, completely empty and which absorbs only as life progresses ever more images, impressions and experiences. Thus, for example, the child will only become aware that fire is hot once he has burned his fingers; he then stores this painful experience away in his understanding and is more careful in future. Perhaps the key statement of empiricism is the one attributed to the English empiricist John Locke “There is nothing in the mind that was not first in the senses”. This was why the empiricists looked on rationalism, with its meditations on God, the Good, justice and other ‘eternal truths’, as mere speculation ; all experience gained through the senses was lacking here. ‘Eternal truths’, indeed, were simply impossible on this view, since every day brought new perceptions, experiments and experiences. Empiricism gained especially wide acceptance in Britain. We have mentioned the Englishmen Locke and Bacon. Other well-known empiricists active in the British Isles were Hobbes, Berkeley and Hume.

Kant’s Brilliant Solution to the ‘Problem of Knowledge’

Who, then, was right: the rationalists or the empiricists? Kant felt torn between the two positions. On the one hand, as a professor of philosophy, he shared the rationalists’ interest in metaphysics: that science of pure mind which is defined as lying ‘beyond physics’; he also sincerely wanted, as did the rationalists, to formulate viable ideas of such things as ‘justice’, ‘right action’, ‘freedom’, and ‘the immortality of the soul’. What disturbed him, however, was the rationalists’ speculative and contradictory way of reasoning, exemplified above all by their so-called ‘proofs of God’. This prompted Kant to mistrust the rationalists and even to describe them as mere ‘dogmatists’ who shook, like stage conjurors, ‘pseudo-proofs’ out of their sleeves:

On the other hand, however, Kant also felt uncomfortable with empiricism. He lived, indeed, in an age highly attentive to the prospects recently opened up by the physics of Newton and recognized the huge progress which he, Copernicus, Kepler and Galileo had made thanks to the empirical method. He knew that the precise empirical observation of natural phenomena, such as the movement of the planets, had enriched human knowledge. But he also saw that the most successful among the physicists had often initially conceived their theories in their minds alone, in purely logical, rational, or even mathematical terms, and had only afterward compared these conceptions with observable events in Nature. And so Kant came to pose the central question: ‘does one, as the empiricists claim, arrive at knowledge only after perceiving through the senses – that is, only a posteriori, to use the technical Latin term meaning ‘afterward’ – or can one possess or acquire knowledge before any sense-perception – or a priori, to use the Latin term meaning ‘prior to’ – that is, through thinking alone:

(The Cambridge Edition of Kant’s writings that is quoted in this book uses – as the reader will have noted – a slightly technical, Latin-based language. For example, what is called ‘cognition’ in the passage above would be called, in ordinary English, just ‘knowing’. The English version differs in this respect from Kant’s original German which used, for ideas like ‘knowing’, the same word as an ordinary German speaker would use. Nevertheless, in order to keep the language of this book in line with the language of the Kant editions quoted, we shall from now on use, besides the common term ‘knowledge, also the more technical terms ‘cognition’ and ‘cognitive’ for the ideas ‘knowing’ and ‘knowledge-related’.)

Kant also describes these a priori acts of cognition supposedly performed by the faculty of reason prior to any actual experience as acts of ‘pure reason’. This is another reason why his main work is called the Critique of Pure Reason; it sets out to examine whether the human thinking apparatus ‘pure an...

Table of contents

• Dedication
• Table of Contents
• Kant’s Great Discovery
• Kant’s Central Idea
• Of What Use Is Kant’s Discovery for Us Today?
• Bibliographical References
• The author
• Copyright