Pure practical reason is the opposite to impure (or sensibly-determined) practical reason and appears in Immanuel Kant's Groundwork of the Metaphysics of Morals.
It is the reason that drives actions without any sensible 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).
Famous quotes containing the words pure, practical and/or reason:
“Already nature is serving all those uses which science slowly derives on a much higher and grander scale to him that will be served by her. When the sunshine falls on the path of the poet, he enjoys all those pure benefits and pleasures which the arts slowly and partially realize from age to age. The winds which fan his cheek waft him the sum of that profit and happiness which their lagging inventions supply.”
—Henry David Thoreau (1817–1862)
“The cycle of the machine is now coming to an end. Man has learned much in the hard discipline and the shrewd, unflinching grasp of practical possibilities that the machine has provided in the last three centuries: but we can no more continue to live in the world of the machine than we could live successfully on the barren surface of the moon.”
—Lewis Mumford (1895–1990)
“Familiarity breeds contempt. How accurate that is. The reason we hold truth in such respect is because we have so little opportunity to get familiar with it.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)