… is from page 218 of Ludwig von Mises’s 1967 paper titled “A Hundred Years of Marxian Socialism” as this paper appeared for the first time, which was in the original 1990 edition of Money, Method, and the Market Process: Essays by Ludwig von Mises (Richard M. Ebeling, ed.):
The philosophy of the Enlightenment considered as its most precious achievement the principle of toleration, the liberty to uphold one’s opinions in religious and philosophical matters without being harassed by the government. It was no less anxious to give to everybody the right to choose the way by which he planned to integrate himself into the system of social cooperation. The great ideal of the age of classical liberalism was liberty, the freedom to make the plans for one’s own life.