Tyler Cowen asks, "Which 20th century classic of American conservative political thought has held up best?" He makes the insightful point that "none have held up particularly well, mostly because they underestimated the robustness of the modern world and regarded depravity as more of a problem than it has turned out to be." NB the qualifiers in the original post: American, not European; conservative, not libertarian; political thought, not economics.
It's a real problem-- one I've often talked with people about in a teaching context, because there's no modern work to teach alongside Theory of Justice and Anarchy, State, and Utopia that really gets at what's interesting about Burkean or social conservatism. Oakeshott's the best 20th c. conservative, but he fails Tyler's "American" test-- and he's at his most teachably conservative in essays, not books. A major underlying theme of the Nomos conference last year on "American conservative thought and politics" was "why the disconnect between political philosophy and conservatism, especially American conservatism?"
The problem isn't just, as conservatives would have it, that the conservative temperament isn't easily reduced to programmatic philosophical works-- that part of its point is not to be so reducible. One of the problems is that history keeps right on going-- and so any book plucked from the past that was concerned with yelling "stop!" tends to date badly to any modern reader who does not think he's already living in hell-in-a-handbasket. This is a particular problem because of race in America-- no mid-20th c work is going to endure as a real, read-not-just-namechecked, classic of political thought that talks about how everything will go to hell if the South isn't allowed to remain the South. Someone like Strauss who didn't care about the American south and didn't write much about the news of his day in any event thus holds up relatively better than someone like Kirk. This is a special case of Tyler's depravity point-- but in the context of 20th c American conservatism, an important special case. And note that Oakeshott has his own version of these problems; doesn't "Rationalism in Politics" end up feeling faintly ridiculous by the time he's talking about women's suffrage?
Count me on both sides of the Road to Serfdom squabble that appears in Tyler's comment thread. Its core historical-necessity thesis has been undermined-- but the relevant country isn't Sweden. Scandinavia and the Low Countries are welfare states but not planned economies. The relevant countries are the Rhine Model countries of France and Germany, plus postwar Japan and South Korea.
I don't see any great answers in the comment thread yet. I guess I might say Schumpeter, Capitalism, Socialism, and Democracy, and Kristol, Two Cheers for Capitalism, but the former isn't really distinctively conservative enough and I'm not sure the latter is a classic.
Update: Brad deLong says "cut the Gordian knot. THERE ARE NO ATTRACTIVE MODERN CONSERVATIVES BECAUSE CONSERVATISM SIMPLY IS NOT ATTRACTIVE. DEAL WITH IT!!" Lizardbreath at Unfogged calls this the "natural conclusion."
To this I say: feh. Scoring points is fun and all, but the point being scored here is entirely beside the, well, point. Brad has no difficulty finding classic teaching texts for views he considers unattarctive-- say, Marxism.
Take something like the standard syllabus of a post-1971 Justice course. theory of Justice; Anarchy, State, and Utopia; Liberalism and the Limits of Justice; Spheres of Justice; After Virtue; Justice, Gender, and the Family; Justice and the Politics of Difference; Liberalism, Community, and Culture; Political Liberalism. Does anyone find the political visions of all of those books attractive? Me, neither. I'm not sure how one could do so. But they're all teachable versions of major, intellectually serious arguments.
John Finnis' Natural Law and Natural Rights and Robert George's Making Men Moral are major, intellectually serious statements of a social conservatism I find deeply unattractive. But for current purposes my problem is not that they're unattractive, it's that they're unteachable-- pitched at too high a level, too drenched in literatures undergraduates in political theory courses won't have read, too Raz-ishly dense (and Raz is hardly teachable to undergraduatess in the first place).
Schmitt's Concept of the Political and Crisis of Parliamentary Democracy provide teachable, cogent, serious statements for a position I trust Brad finds "unattractive." So does Maistre. Why is it easier to find enduring reactionary texts than enduring texts that state the basic position of conservatives in liberal democracies? That's the puzzle.
Another update: Last word to Brad. I'm supposed to do some more-sustained thinking and writing on this question sometime soon. I'll report back with new contributions then.
One more update: My colleague Will Roberts may have it just right.
I think Jacob has answered his own question, actually. Fundamentally, conservatives (in the relevant Burke-to-Buckley-to-Sullivan sense) are liberals (in the classical sense) who worry about cultural decay. That is, they agree with liberals that subjective freedom is the end of the political community, but think that market freedom needs a basis in certain cultural institutions in order to be stable and lasting. Those institutions are always being whittled away by the drip-drip-drip of market freedoms, so conservatives self-avowedly find themselves repeatedly "standing athwart history yelling Stop!" The trouble is, as Jacob says, "history keeps right on going." The drip-drip-drip keeps eroding the cultural institutions, and conservatives have to take some new stand.
To be a teachable classic, a work has to touch something enduring, and conservative texts tend to be caught up in the present crisis.