Pure practical reason (German: reine praktische Vernunft) is the opposite of impure (or sensibly-determined) practical reason and appears in Immanuel Kant's Critique of Practical Reason and Groundwork of the Metaphysic of Morals.

It is the reason that drives actions without any sense-dependent incentives. Human reasoning chooses such actions simply because those actions are good in themselves; this is the nature of good will, which Kant argues is the only concept that is good without any justification, it is good in itself and is a derivative of a transcendental law which affects the way humans practically reason (see practical philosophy).

References

• Immanuel Kant, Kritik der praktischen Vernunft, Stuttgart 1961, "Vorrede".
• Immanuel Kant, Grundlegung zur Metaphysik der Sitten, Vandenhoeck & Ruprecht, 2004, p. 106.