Liberals think of politics as a means; conservatives as an end. Politics, for liberals, stops at the water's edge; for conservatives, politics never stops. Liberals think of conservatives as potential future allies; conservatives treat liberals as unworthy of recognition. Liberals believe that policies ought to be judged against an independent ideal such as human welfare or the greatest good for the greatest number; conservatives evaluate policies by whether they advance their conservative causes. Liberals instinctively want to dampen passions; conservatives are bent on inflaming them. Liberals think there is a third way between liberalism and conservatism; conservatives believe that anyone who is not a conservative is a liberal. Liberals want to put boundaries on the political by claiming that individuals have certain rights that no government can take away; conservatives argue that in cases of emergency -- conservatives always find cases of emergency -- the reach and capacity of the state cannot be challenged.
And another, not irreconcilable approach (via Digby):
From the pharaohs of ancient Egypt to the self-regarding thugs of ancient Rome to the glorified warlords of medieval and absolutist Europe, in nearly every urbanized society throughout human history, there have been people who have tried to constitute themselves as an aristocracy. These people and their allies are the conservatives.
The tactics of conservatism vary widely by place and time. But the most central feature of conservatism is deference: a psychologically internalized attitude on the part of the common people that the aristocracy are better people than they are. Modern-day liberals often theorize that conservatives use "social issues" as a way to mask economic objectives, but this is almost backward: the true goal of conservatism is to establish an aristocracy, which is a social and psychological condition of inequality. Economic inequality and regressive taxation, while certainly welcomed by the aristocracy, are best understood as a means to their actual goal, which is simply to be aristocrats. More generally, it is crucial to conservatism that the people must literally love the order that dominates them. Of course this notion sounds bizarre to modern ears, but it is perfectly overt in the writings of leading conservative theorists such as Burke. Democracy, for them, is not about the mechanisms of voting and office-holding. In fact conservatives hold a wide variety of opinions about such secondary formal matters. For conservatives, rather, democracy is a psychological condition. People who believe that the aristocracy rightfully dominates society because of its intrinsic superiority are conservatives; democrats, by contrast, believe that they are of equal social worth. Conservatism is the antithesis of democracy. This has been true for thousands of years.
Hyperbole? Oh, many would like to think so. And many conservative would argue that these contentions are ridiculous (of course they would; only hardly wants to be on the side of fascists and aristocrats.) But I don't think so, and the history of the last six years bears me out.