The nature of conservatism as an institutional ideology precludes any permanent and inherent affiliation or opposition between it and any particular ideational ideology. No necessary dichotomy exists, therefore, between conservatism and liberalism. The assumption that such an opposition does exist derives, of course, from the aristocratic theory of conservatism and reflects an overconcern with a single phase of western history at the end of the 18th and the beginning of the 19th centuries. The effort to erect this ephemeral relationship into a continuing phenomenon of political history only serves to obscure the fact that in the proper historical circumstances conservatism may well be necessary for the defense of liberal institutions. The true enemy of the conservative is not the liberal but the extreme radical no matter what ideational theory he may espouse. Different radicals advance different panaceas, but they all have the same psychology which conservative thinkers have not been slow to identify. Hooker's sixteenth-century Puritan, Metternich's "presumptuous man," Burke's "metaphysical scribbler," Hawthorne's Hollingsworth, Cortés' "self-worshipping man," Hoffer's twentieth century "true believer," are all one and the same.
(Samuel P. Huntington, "Conservatism as an Ideology," The American Political Science Review 51 [June 1957]: 454-73, at 460)
Note from KBJ: And now you know why I don't talk much about liberalism. The enemy of conservatism is progressivism, not liberalism.