book1788

Critique of Practical Reason

Disciplines:

Summary

Kant's Critique of Practical Reason (1788) establishes the rational foundations of morality and argues for the postulates of practical reason — God, freedom, and immortality.

Core Contribution

Kant argues that pure reason alone — without appeals to experience or consequences — can determine the moral law; the categorical imperative is derived from pure practical reason, and the postulates of freedom, God, and immortality are necessary conditions for the possibility of morality.

Key Spikes & Highlights

Autonomy of pure practical reason (morality is self-legislated by reason; heteronomous grounding in inclination or consequences fails)
Postulates of immortality and God (not knowledge claims but necessary conditions — we must act as if the moral order will be vindicated)
Highest good (virtue should be rewarded with happiness; this requires God and immortality as the guarantors of cosmic justice)
Feeling of respect (the only purely moral feeling — not pleasure or pain but the awe we feel before the moral law)

Historical Influences

Immanuel Kant

Intellectual Lineage

Kantian critical philosophy Rationalist ethics

Allied Works

Groundwork for the Metaphysics of Morals Critique of Pure Reason Critique of Judgment

Contemporaries & Peers

Groundwork for the Metaphysics of Morals Critique of Pure Reason Critique of Judgment

Minds Influenced

No recorded minds influenced.

Intellectual Posterity

Moral law from reason alone Postulates of practical reason

Discussing