Steven Hayward, writing at Powerline, starts the discussion of conservative vs. liberal and what those two terms really mean today. I thought it only appropriate to call it to the attention of our resident scholar in matters definitional, Black3, and harvest the veritable cornucopia of knowledge that shall issueth forth:

Start at the beginning.  In the broadest terms, what is liberalism, and what is conservatism?  My own shorthand definition is that liberalism is the view that individuals should be free to pursue their own self-chosen purposes, so long as their choices do not harm others.  This is no more than a one-sentence distillation of John Stuart Mill’s explication of the liberal idea in On Liberty, a rich and variegated argument which, ironically, contains many postulates for both left and right today.  But this raises the first conceptual difficulty: conservatives also favor individual liberty in some form; conservatives especially favor maximum economic liberty.  Liberals are for “rights;” so are conservatives—sometimes even the same “rights,” sometimes not.  Is conservatism merely a branch or dissident strain of liberalism, or does it represent a fundamental alternative to understanding and prescribing social life and political institutions?

Defining conservatism succinctly is not as easy as defining liberalism for precisely this reason, and it raises immediately the split within the political right between traditional conservatives who speak of “ordered liberty” and libertarians who believe “ordered liberty” to be oxymoronic; see especially Friedrich Hayek’s famous essay “Why I Am Not a Conservative,” in which he concludes that “I doubt whether there can be such as thing as a conservative political philosophy.”  William F. Buckley, Jr. found it impossible to define conservatism succinctly, and when pressed would “punish” inquirers with linguist Richard Weaver’s formulation that conservatism is “the paradigm of essences towards which the phenomenology of the world is in continuing approximation.”

This definition is not as ridiculous as it sounds, though it does need translation into plain English.  The broadest common denominator for conservatism may be a distillation of Russell Kirk’s six-part definition (from The Conservative Mind) into seven words—a belief in a transcendent moral order—with two caveats or qualifications.  First, it is not necessary to be religious or even a theist to embrace this premise; it can arise from purely secular origins alone (i.e., classical philosophy).  Second, this definition can comprise most libertarian thought, at least insofar as libertarians believe that social structures and market processes are bounded by the laws of nature, even if those laws are not clear or permanently fixed.

This last point brings us right to the crux of the theoretical divide, as libertarianism provides the bridge between liberalism and conservatism in the abstract.  Libertarianism embraces the freedom and innovation (social and otherwise) that modernization brings, while preserving fixed limits to how much or how far political intervention, or centralized knowledge, can go in shaping change.  The traditional conservative, who often comes to sight as a categorical opponent of change, is not necessarily opposed to all change in principle, but differs from the libertarian chiefly as a matter of degree rather than kind.  This is why the attempts to form a “liberaltarian” coalition were doomed to failure (liberals acknowledge few if any limits on the reach of political power to solve social ills), and why traditional conservatives and libertarians, despite differences on particular issues such as abortion or drugs, will generally remain politically allied.