Notes on Kant

Immanuel Kant
The Powers and Limits of the Mind
I. Kant’s significance
Philosophy is divided between pre-Kantian and post-Kantian periods.
He began as a rationalist, influenced by Christian Wolff, who wrote a book entitled Reasonable Thoughts on God, the World, the Soul of Man, and All Things in General.” This kind of reminds me of Douglas Adams’ book “The World, the Universe and Everything,” except Wolff was serious! Wolff was a follower of G. W. Leibniz, the third of the Continental Rationalists.
Was “awakened from his dogmatic slumbers” by the skeptical writings of David Hume. His plan was to combine the rational confidence of the rationalists with the insights of the empiricists without falling into either dogmatism or skepticism.

II. Kant’s key assumption
Kant’s key assumption is that we do have knowledge, found in math and in science.
Kant agreed with the rationalists that genuine knowledge must be universal, necessary and certain, but he knew that perception was essential to the operation of science.
He agreed with the empiricists that all knowledge begins with experience.
III. Difficulties with empiricism
Hume had pointed out that experience alone cannot give us universal, necessary and certain knowledge.
Connections between items of experience, for Hume, is a matter of psychological habit.
Thus Hume could find no grounds for believing that our minds conform to an objective, external world.

IV. Kant’s goals
To put science on a secure foundations and steer between rationalism and empiricism.
To reconcile mechanistic science on the one hand with religion, morality and human freedom.
To address the crisis of metaphysics. Rationalist metaphysics and theology had said we could know various realities that transcended experience, but they all disagreed with one another. Descartes was a dualist, Spinoza was a pantheist, and Leibniz was an idealist. But the solution is not to commit all books on metaphysics to the flames, indeed we can no more stop doing metaphysics than we can stop breathing. So getting metaphysics off the ground by, paradoxically, setting limits for it is another of Kant’s three goals.
V. Critical Philosophy
As opposed to dogmatic philosophy, Kant called his own philosophy critical philosophy.
His most important work is called the Critique of Pure Reason. He determined to find out what pure reason is capable of, and what it is not capable of. The pure reason he is talking about is theoretical reason rather than practical reason.
VI. Kant’s Copernican Revolution
Kant agrees with the empiricists that all knowledge begins with experience.
But it doesn’t all arise out of experience.
Copernicus’ revolution with respect to our understanding of the solar system was achieved by changing the center of focus.
The empiricists thought the mind was passive in confronting the world. On this picture, knowledge conforms to its objects. Kant turned this around and said that objects conform to knowledge. For sense data to be experienced as objects by us, our mind must impose a certain structure on them.
VII. Appearance and Reality
Kant makes a distinction between the way reality appears to us and the way it is in itself. The way it appears to us (the only reality we can know) depends on both the sense and the intellect, or mind. What we see is not what is there in itself, but what appears to us when we put our glasses on.
When we become aware of objects, the mind has already done its work.
VIII. Varieties of judgments
Analytic judgments are based on the principle of contradiction: All bachelors are unmarried.
Synthetic judgments give us new information about the world.
A priori knowledge is knowledge that can be obtained independently of experience.
A posteriori knowledge is knowledge obtained from experience
IX. Four combinations
Analytic a priori judgments, or Humean relations of ideas.
Analytic a posteriori judgments. No such thing. If it’s analytic we don’t learn it by experience. Hence a research study on the marital status of bachelors would be a waste of money indeed.
Synthetic a posteriori judgments. Humean matters of fact. Known through experience.
Synthetic a priori judgments. For Hume these do not exist, but this left big holes in Hume’s theory of knowledge which he had to fill with sentiment, custom, and habit. Kant, however, claims that there are indeed such judgments. For example, for Kant “All events have a cause” is synthetic a priori, as is (contrary to Hume), the truths of mathematics.