Immanuel Kant was popular at his death. The whole town emptied out to see him. His last words were "it is good". But was his philosophy any good? In order to find out, we dive into Chapter 7 of Conjectures and Refutations: Kant’s Critique and Cosmology, where Popper rescues Kant's reputation from the clutches of the dastardly German Idealists.
We discuss
Deontology vs consquentialism vs virtue ethics
Kant's Categorical Imperative
Kant's contributions to cosmology and politics
Kant as a defender of the enlightenment
Romanticism vs (German) idealism vs critical rationalism
Kant's cosmology and cosmogony
Kant's antimony and his proofs that the universe is both finite and infinite in time
Kant's Copernican revolution and transcendental idealism
Kant's morality
Why Popper admired Kant so much, and why he compares him to Socrates
Quotes
Enlightenment is man's emergence from his self-imposed immaturity. Immaturity is the inability to use one's understanding without guidance from another. This immaturity is self-imposed when its cause lies not in lack of understanding, but in lack of resolve and courage to use it without guidance from another. Sapere Aude! "Have courage to use your own understanding!" --that is the motto of enlightenment.
- An Answer to the Question: What is Enlightenment? (Translated by Ted Humphrey, Hackett Publishing, 1992)
(Alternate translation from Popper: Enlightenment is the emancipation of man from a state of self-imposed tutelage . . . of incapacity to use his own intelligence without external guidance. Such a state of tutelage I call ‘self-imposed’ if it is due, not to lack of intelligence, but to lack of courage or determination to use one’s own intelligence without the help of a leader. Sapere aude! Dare to use your own intelligence! This is the battle-cry of the Enlightenment.)
- C&R, Chap 6
What lesson did Kant draw from these bewildering antinomies? He concluded that our ideas of space and time are inapplicable to the universe as a whole. We can, of course, apply the ideas of space and time to ordinary physical things and physical events. But space and time themselves are neither things nor events: they cannot even be observed: they are more elusive. They are a kind of framework for things and events: something like a system of pigeon-holes, or a filing system, for observations. Space and time are not part of the real empir- ical world of things and events, but rather part of our mental outfit, our apparatus for grasping this world. Their proper use is as instruments of observation: in observing any event we locate it, as a rule, immediately and intuitively in an order of space and time. Thus space and time may be described as a frame of reference which is not based upon experience but intuitively used in experience, and properly applicable to experience. This is why we get into trouble if we misapply the ideas of space and time by using them in a field which transcends all possible experience—as we did in our two proofs about the universe as a whole.
...
To the view which I have just outlined Kant chose to give the ugly and doubly misleading name ‘Transcendental Idealism’. He soon regretted this choice, for it made people believe that he was an idealist in the sense of denying the reality of physical things: that he declared physical things to be mere ideas. Kant hastened to explain that he had only denied that space and time are empirical and real — empirical and real in the sense in which physical things and events are empirical and real. But in vain did he protest. His difficult style sealed his fate: he was to be revered as the father of German Idealism. I suggest that it is time to put this right.
- C&R, Chap 6
Kant believed in the Enlightenment. He was its last great defender. I realize that this is not the usual view. While I see Kant as the defender of the Enlightenment, he is more often taken as the founder of the school which destroyed it—of the Romantic School of Fichte, Schelling, and Hegel. I contend that these two interpretations are incompatible.
Fichte, and later Hegel, tried to appropriate Kant as the founder of their school. But Kant lived long enough to reject the persistent advances of Fichte, who proclaimed himself Kant’s successor and heir. In A Public Declaration Concerning Fichte, which is too little known, Kant wrote: ‘May God protect us from our friends. . . . For there are fraudulent and perfidious so-called friends who are scheming for our ruin while speaking the language of good-will.’
- C&R, Chap 6
As Kant puts it, Copernicus, finding that no progress was being made with the theory of the revolving heavens, broke the deadlock by turning the tables, as it were: he assumed that it is not the heavens which revolve while we the observers stand still, but that we the observers revolve while the heavens stand still. In a similar way, Kant says, the problem of scientific knowledge is to be solved — the problem how an exact science, such as Newtonia