Immanuel Kant

He pushed Kant's autonomy to its limit: not only the moral law but the whole world is posited by the I.

He accepted Kant's critical turn but rejected the thing in itself and fixed categories: contradiction is not reason's failure but its life.

He saw himself as Kant's one true heir: the distinction of appearance and thing in itself is right, but the thing in itself is not unknowable, it is Will.

His lifelong project was a 'Critique of Historical Reason': what Kant had done for the natural sciences he would do for the human sciences.

He said that as a young man he read the Critique of Pure Reason two hours a day for three years until he nearly knew it by heart. The doctrine of categories was the starting point of his life's work.

He agreed with Kant that geometry is synthetic a priori but set out to show that arithmetic is analytic: number can be derived from logic alone, without intuition.

He rejected Kant's treatment of time as a form of intuition on a par with space: real time is duration, which can be neither spatialised nor cut up by concepts.

His fellowship dissertation was on Kant's ethics; he then rejected transcendental idealism wholesale and held that objects exist independently of consciousness.

Kant was his 'philosopher of philosophers': the limits of reason are not a failure but the place where the Transcendent can show itself.

Her late Lectures on Kant's Political Philosophy read out of the Critique of Judgement a politics centred on the spectator's judgement, the one Kant himself never wrote.

Ricoeur called his structuralism 'Kantianism without a transcendental subject', and he accepted the label: universal structures of mind, but located not in a subject, in unconscious rules.

Anomalous monism is a Kantian solution: the opposition of mind and nature is kept at the level of description and abolished at the level of ontology, letting freedom and causality coexist.

The original position is a procedural rendering of Kant's autonomy: those who choose principles behind the veil of ignorance treat themselves as free and equal rational beings.

Late in life he called himself 'a Kantian with movable categories': paradigms constitute experience like Kant's categories, except that they change with history.

In his last decades he read the third Critique again and again; the sublime, the failure of imagination before what cannot be presented, became his key to modern art and the postmodern condition.

His secondary thesis translated and commented on Kant's Anthropology, and in his last years he returned to 'What is Enlightenment?', defining critique as a historical ontology of ourselves.

'Internal realism' claimed Kantian descent: there is no God's-eye view, truth is idealised rational acceptability, yet this is not relativism.

His discourse ethics is the dialogical version of the categorical imperative: a norm is valid if and only if all affected could agree to it in rational discussion.

His subjective–objective problem is the contemporary version of Kant's: how a being that can view from nowhere yet must live from somewhere can hold itself together.

'Humanity as an end' becomes in his hands the 'side constraint' of rights: no one may be used for others' benefit, even for a greater aggregate good.

On What Matters tries to show that Kantianism, contractualism and consequentialism are 'climbing the same mountain on different sides' and will meet at the summit.