Immanuel Kant

Background

Immanuel Kant (1724–1804), who spent his entire career at the University of Königsberg, occupies a unique double position in this wiki: he is at once the most influential critic of the theoretical proofs of God's existence and the architect of a practical route back to theism. The critical side is the Critique of Pure Reason's demolition of the ontological proof: "Being is evidently not a real predicate, that is, a conception of something which is added to the conception of some other thing… The proposition, God is omnipotent, contains two conceptions… the word is, is no additional predicate," so that "a hundred real dollars contain no more than a hundred possible dollars" (Kant, CPR, 'Of the Impossibility of an Ontological Proof'). If existence adds nothing to a concept, it cannot be a perfection or great-making property.

The constructive side runs through the second Critique: the moral law obliges us to promote the summum bonum — virtue crowned with proportionate happiness — which is "possible only on condition of the existence of God"; hence "it is morally necessary to assume the existence of God" (Kant, CPrR, 'The Existence of God as a Postulate of Pure Practical Reason'). The Religion draws the systematic consequence: "Ethic issues, then, inevitably in Religion, by extending itself to the idea of an Omnipotent Moral Lawgiver" (Kant 1793, Preface to 1st ed.).

Positions held in this wiki

• The Ontological Argument — the existence-is-not-a-predicate objection, third strand of the Gaunilo–Hume–Kant critical line. Note: the article cites Kant only via the SEP with an {{UNSOURCED}} flag; the Critique of Pure Reason (Meiklejohn trans.) is now in corpus, so that flag can be retired at the next compile pass.
• The Moral Argument for God — the postulate of practical reason: not "God exists" but "I, as a rational moral agent, ought to believe that God exists."
• Mentioned in The Leibnizian (Contingency) Cosmological Argument as the source of the objection that contingency arguments covertly rely on the ontological argument.

Key works in our corpus

• Critique of Pure Reason (1781/1787, Meiklejohn trans.) — in corpus (new). Transcendental Dialectic, 'The Ideal of Pure Reason': the real-predicate passage and the hundred-dollars illustration.
• Critique of Practical Reason (1788) — in corpus (new). Dialectic, ch. II, §V: the God-postulate in full.
• Religion within the Boundary of Pure Reason (1793, Semple trans. 1838) — in corpus. The preface's hinge from autonomous ethics to religion.

Principal critics

• Alvin Plantinga — the modal revival: Anselm's own Apologetic, on the SEP's reading, does not rely on the premise Kant attacks; and the S5 argument bypasses existence-as-predicate entirely.
• Robert Merrihew Adams — the obligation-weakening reply to the practical argument: we are obliged only to approximate the highest good, not to achieve it.
• Friedrich Nietzsche — the genealogical assault on the authority of the moral law itself, the practical argument's sole premise.

See also

• Anselm of Canterbury, René Descartes, Gottfried Wilhelm Leibniz — the targets of the first Critique's attack.
• David Hume — the skeptical predecessor who, by Kant's own account, interrupted his dogmatic slumber.
• William Lane Craig — the contemporary evidentialist program that must answer Kant on both flanks.