German Idealism

The claim

The mind does not passively receive a world; it supplies the form in which any world can appear. Space, time and the categories are conditions of experience rather than discoveries about things in themselves.

What it held

Kant's Copernican turn is the founding move. Instead of asking how our knowledge conforms to objects, ask how objects must conform to our knowledge — and the answer explains why mathematics and physics can be both necessary and about the world, which nothing before had managed.

The cost is the thing in itself: reality as it is apart from our forms of experience, which we cannot know. Kant's successors found this intolerable. If it is unknowable, why posit it? And if it causes our sensations, causation has been applied beyond experience, which Kant forbade.

Fichte's answer is to drop it and begin from the self-positing I. Schelling adds nature as spirit not yet awake. Hegel's is the most ambitious: the opposition between thought and being is itself a stage in thought's development, and philosophy's task is to follow the movement by which each position generates the contradiction that carries it forward.

The fifty years from the first Critique to Hegel's death produced more systematic philosophy than any comparable stretch, and everything after in the continental tradition is a response.

How it argued

Transcendental argument — establishing what must be true for experience to be possible at all — then, in Hegel, dialectical development as an alternative to argument from fixed premises.

What it was arguing against

Both rationalist dogmatism and empiricist scepticism, which Kant regarded as jointly exhausting the failed options.

Where it disagreed with itself

The thing in itself. Whether Hegel's dialectic is a method or a description. Whether the systems are readable at all, which even sympathetic contemporaries doubted.

Common misconceptions

That idealism means the world is mental. Kant's transcendental idealism is compatible with realism about ordinary objects and explicitly asserts it — he calls his position empirical realism.

How it began

Kant reading Hume, waking from what he called his dogmatic slumber, and spending eleven silent years writing the Critique of Pure Reason.

What became of it

Collapsed rapidly after Hegel's death in 1831, split into Left and Right Hegelians, and repudiated by almost everyone before being repeatedly revived.

Lasting influence

Marx, Kierkegaard, Nietzsche and the whole of continental philosophy are reactions to it. Analytic philosophy began partly as a revolt against its British form.

Why it still matters

The question of how much of what we experience is contributed by us is a live one in philosophy of mind and cognitive science, in almost Kant's terms.

Put another way

Spectacles you cannot remove, and an argument about whether there is anything to see without them.

Where to start

The Prolegomena, Kant's own short restatement written because nobody understood the Critique.

The surprising bit

Kant published nothing significant for eleven years while writing the first Critique, then wrote it in four or five months and apologised for the prose.

In their own words

Connections

Answers

British Empiricism, Spinozism

Opposed by

British Empiricism, Vienna Circle

Influenced

Hegelianism, Fichteanism, Neo-Kantianism, Classical Marxism, Naturphilosophie

The verdict

The most concentrated burst of system-building in the history of philosophy, and the one everything since has had to answer.

Sources

• Stanford Encyclopedia of Philosophy