Early modern Europe · 1781 – c. 1930 (Neo-Kantianism)
Kant’s critical philosophy
Our minds do not passively copy the world: space, time and concepts such as cause are forms we bring to all experience.
What can I know? What ought I to do? What may I hope?
By the 1770s rationalist metaphysics seemed to produce endless unresolved disputes, while Hume’s empiricism threatened to dissolve causation and with it the certainty of Newtonian science. Kant, trained in the Leibniz–Wolff school, said Hume had woken him from his “dogmatic slumber”, and set out to examine the powers and limits of reason itself.
We have knowledge that is both necessary and about the world — in geometry, and in the principle that every event has a cause — yet experience can never show necessity. Kant concluded that such knowledge is possible only because the mind supplies the forms through which anything can appear to us; the price is that we know things only as they appear, never as they are in themselves.
- Experience is shaped by forms the mind contributes a priori.
- We know appearances, never things as they are in themselves.
- Morality is a law of reason: treat persons always as ends.
Kant’s “Copernican revolution” framed nearly all later philosophy: German idealism grew from it, Neo-Kantians led German universities until about 1930, and Kantian ethics underlies modern ideas of human dignity.
Thinkers
1724–1804Immanuel KantKönigsberg professor whose critical philosophy redrew modern thoughtKey texts
Where it came from
Grew out ofRationalismKant was trained in the Leibniz–Wolff school and kept its conviction that some knowledge is a priori, while denying that pure reason can reach beyond experience.Reacted against
British empiricismHume’s attack on causal necessity woke Kant from his “dogmatic slumber”; Kant answered that causality is a category the mind brings to experience, not something learned from it.Grew out of
The EnlightenmentKant’s essay “What Is Enlightenment?” (1784) defined the movement as daring to use one’s own understanding, and his ethics of autonomy carried its ideals.
What it led to
Carried on byGerman IdealismFichte, Schelling and Hegel set out to complete Kant’s critical philosophy by removing the unknowable thing in itself and deriving everything from a single principle.Carried on by
HermeneuticsDilthey sought a “critique of historical reason” to do for the human sciences what Kant had done for natural science.Carried on by
PragmatismPeirce, a close reader of the Critique of Pure Reason, took the very word “pragmatic” from Kant.Opposed by
Logical positivism (Vienna Circle)Several members started as Neo-Kantians, but all came to reject Kant’s synthetic a priori truths, partly because relativity overturned the Euclidean space Kant thought necessary.Carried on by
Liberal theories of justice (Rawls and after)Rawls offered a “Kantian interpretation” of justice as fairness: the original position models persons as free and equal rational agents.Opposed by
Virtue ethics revivalVirtue ethicists rejected morality as obedience to universal rules, and Anscombe called Kant’s idea of legislating for oneself absurd.Borrowed by
New ConfucianismMou Zongsan translated Kant’s three Critiques and framed Confucian ethics as completing what Kant left open: intellectual intuition of the moral self.
Its answers to the big questions
KnowledgeHow can we know anything?Experience supplies the content, the mind the form: we know appearances, not things in themselves.EthicsHow should one live?Act only on rules you could will everyone to follow, and never treat a person merely as a means.On the record
Kantianism is drawn until c. 1930, the end of Neo-Kantianism.
Neo-Kantianism was the dominant movement in German philosophy from about 1870 until the First World War; its standing collapsed in the decades after 1918, and Hitler’s rise in 1933 nearly erased its institutions. An end around 1930 is a reasonable convention. The other end years in this tradition (rationalism mid-18th century, empiricism 1776, social contract 1790, German idealism 1840s) are likewise cut-offs for the map, not events.
Sources: Stanford Encyclopedia of Philosophy, “Neo-Kantianism”