… is from page 268 of philosopher Gary Madison’s 1986 book, The Logic of Liberty, as quoted on page 277 of Don Lavoie’s review – titled “A Political Philosophy of the Market Process” – of Madison’s book in The Market Process (Peter J. Boettke & David L. Prychitko, eds., 1994) (ellipses added by Lavoie):
If individual liberty is a fundamental value, it is not because it contributes to an individual’s private “happiness” or “pleasure,” but because it is the necessary condition for implementing the principle of human dignity…
Anyone who would prefer slavery to freedom (for the security it offers, perhaps) would thereby demonstrate, not that freedom is not a supreme value, but only his own deficiency as a human being.