… is from page 230 of F.A. Hayek’s 1961 speech “The Moral Element in Free Enterprise,” which is reprinted as chapter 16 in Hayek’s 1967 collection, Studies in Philosophy, Politics, and Economics:
[F]reedom, if it is to work well, requires not only strong moral standards but moral standards of a particular kind, and that it is possible in a free society for moral standards to grow up which, if they become general, will destroy freedom and with it the basis of all moral values.
