In The Constitution of Liberty (Chicago: The University of Chicago Press, 1960)

Excerpt:

At a time when most movements that are thought to be progressive advocate further encroachments on individual liberty, those who cherish freedom are likely to expend their energies in opposition. In this they find themselves much of the time on the same side as those who habitually resist change. In matters of current politics today they generally have little choice but to support the conservative parties. But, though the position I have tried to define is also often described as “conservative,” it is very different from that to which this name has been traditionally attached. There is danger in the confused condition which brings the defenders of liberty and the true conservatives together in common opposition to developments which threaten their ideals equally. It is therefore important to distinguish clearly the position taken here from that which has long been known — perhaps more appropriately — as conservatism.

Online:
Cato Institute [pdf]