… is from page 263 of F.A. Hayek’s December 1961 speech in New York City titled “The Moral Element in Free Enterprise,” which appears as chapter twenty of Essays on Liberalism and the Economy (2022) – volume 18 (expertly edited by Paul Lewis) of The Collected Works of F.A. Hayek:
Economic activity provides the material means for all our ends. At the same time, most of our individual efforts are directed to providing means for the ends of others in order that they, in turn, may provide us with the means for our ends. It is only because we are free in the choice of our means that we are also free in the choice of our ends.