Kant: The Copernican Revolution in Philosophy

What Awakened Kant

Immanuel Kant (1724–1804) spent his entire life in Königsberg, venturing outside its limits only for a few miles. He lectured precisely by schedule, took walks at the same time daily—city residents set their clocks by him. But at 57 years old, the "Critique of Pure Reason" (1781) overturned Western philosophy.

He called Hume his teacher, who "awakened him from dogmatic slumber." Hume showed that neither empiricism (Locke) nor rationalism (Descartes, Leibniz) can substantiate our knowledge about the world. Kant set himself the task: to find a third way.

The Copernican Revolution

Before Copernicus, people thought: the Sun revolved around the Earth. Copernicus reversed this: the Earth revolves around the Sun. Kant applied this revolution to the theory of knowledge. Before him, people thought: knowledge is formed by the object, which acts upon a passive mind. Kant reversed: the mind actively structures experience. Objects are subject to the forms of our cognition, not the other way around.

Kant calls these forms a priori (preceding experience): space, time, causality, substance. We do not extract them from experience—we bring them to experience. We see the world structured through these categories because that is how our mind works. But what the world is "in itself", independent of our perception—the thing in itself (Ding an sich)—is fundamentally unknowable.

Consequence: science is objective within the bounds of human experience. Newtonian mechanics describes the world of phenomena with complete rigor. But when it goes beyond these limits—speaks about God, free will, immortality—reason begins to contradict itself. These are antinomies of reason: one can prove both that the world is finite and that it is infinite; both that the will is free and that everything is determined. Reason steps beyond possible experience—and wanders.

The Categorical Imperative

"Critique of Practical Reason" (1788)—Kant’s ethics. His question: what does it mean to act morally? Answer: only that action is moral which is done out of duty—not out of fear, self-interest, or sympathy.

The principle of morality—the categorical imperative—is an unconditional requirement. Three formulations:

1. "Act only according to that maxim whereby you can at the same time will that it should become a universal law." The test for universalizability: if everyone were to lie, language would cease to work as a tool of communication. Therefore, one cannot lie.

2. "Act so that you always treat humanity, whether in your own person or that of any other, as an end and never merely as a means." People are intrinsically valuable. One cannot use a person as an instrument.

3. Act as the legislator of a universal kingdom of ends—as if you were establishing a law for all humankind.

These principles exerted enormous influence on legal philosophy, bioethics, business ethics. When a company asks "What if all companies acted this way?"—this is Kantian logic.

"Critique of Judgment" and Aesthetics

The third "Critique" (1790)—on beauty and purposiveness. Judgment of taste—"this is beautiful"—is not simply subjective (like, I enjoy it) and not simply objective (like a mathematical truth). It claims universal agreement, but does not require a concept. Beauty is purposiveness without purpose.

Kant is a synthesizing figure of the era. His disciples diverged in opposite directions: Fichte, Schelling, Hegel built grand idealist systems; British philosophers (Mill, Bentham) moved toward utilitarianism; Schopenhauer, Kierkegaard, Nietzsche renounced rationalism.

Question for reflection: The categorical imperative requires: act so that the principle of your action could become a universal law. Test your latest difficult ethical decision in practice: would it pass this test?