Don Boudreaux completely missed the point - that Brooks was calling out conservative and libertarian social engineers and radicals as well as liberal ones. Boudreaux regularly advocates these huge imposed changes, derived from deduction from simple principles rather than real testing in the real world - precisely the sort of change that Burke and the Scottish Enlightenment were disposed against.
Greg Mankiw gets Brooks's point, and has this great anecdote:
"A couple years ago, I participated in a panel discussion on libertarianism in Mike Sandel's Justice class, along with my friend and colleague Jeff Miron. Jeff is a true libertarian, and he defended that position with gusto. By comparison to Jeff, I seemed lacking in conviction. I described myself as a "libertarian at the margin." By that, I meant that given our starting point today, I believe more reliance on individual liberty and less on governmental solutions is usually a step in the right direction, but I often recoil at more radical libertarian positions.
David Brooks's column yesterday offers a good explanation of skepticism about big radical ideas, such as pure libertarianism. It made me feel better about my watered-down variety."
I regularly say I'm sympathetic to Austrians and libertarians here. I think I'm clear on how I'm sympathetic. I highlight their ideas that I agree with all the time, despite the fact that I also critique. Sure - I praise Hayek and Boettke and Garrison more than I praise Mises and Salerno and Rothbard, but I'm allowed to have preferences. Anyway - my sympathy is of the Mankiw variety, and I think he and Brooks nail it. Boudreaux, as usual, completely misses the point.
Beware of libertarian social engineers, and any radical social engineers that have a massive mega-project they want to impose on society based on a huge system they've built up from some first principles. John Dewey cautions against this and highlights the point about rationalism in The Quest for Certainty:
"From the side of the object those who put forward the claims of reason have placed the universal higher than the individual; those who have held to perception have reversed the order. From the side of mind, one school has emphasized the synthetic action of conceptions. The other school has dwelt upon the fact that in sensation the mind does not interfere with action of objects in writing their own report. The opposition has extended to problems of conduct and society. On one hand, there is emphasis upon the necessity of control by rational standards; on the other hand, the dynamic quality of wants has been insisted upon together with the intimately personal character of their satisfaction as against the pure remoteness of pure thought. On the political side, there is a like division between the adherents of order and organization, those who feel that reason alone gives security, and those interested in freedom, innovation and progress, those who have used the claims of the individual and his desires as a philosophical basis."
I'm not sure the distinction is quite so sharp (and Rothbard offers an entirely opposite thesis here), but Dewey makes the right point. When you think you can just think up the best way for society to be organized, you'll countenance radical changes and impositions of a new social order on society far more easily. Movements like Communism were at least explicit about this. I think one of the biggest dangers of libertarianism is that since it is ostensibly a doctrine of individual liberty, the fact that an entirely new, theoretical order is imposed on society is obscured. Try telling a libertarian they're imposing a grand plan for a new social order and watch the steam come out of their ears either because (1.) they're furious, or (2.) they can't process the accusation - it makes no sense to them. In fact I'm sure I'll hear a little of both in the comment section (which I probably won't be able to attend to today).
Remember, for all they belly-ache about their claims to classical liberalism, libertarianism largely emerged out of French liberalism and the French Enlightenment - not the British. I'm not saying even that the French Enlightenment is a bad thing (and I don't think Brooks is saying that either). Everyone makes their own unique errors - but it's important to be cognizant about what those errors are and what the implications are, even for fellow liberals.
UPDATE: So when people write, they don't fact check every single word - we write on the basis of the wealth of knowledge that we've collected and stored over the years. Every once in a while, though, it's good to double-check some things. After publishing this I decided to double check my claim about the roots of libertarianism in French liberalism. I found enough to conclude that as a general statement it's a fine statement for me to make - I'm not claiming that there were no other influences after all, and the French vein seems to be substantial, consequential, and freely acknowledged by libertarians. While double-checking this, though, I stumbled across an interesting (admittedly, from Wikipedia) point about the origins of libertarianism. When the word first emerged in France, it was in a critique of Proudhon. The accusation was that he was "liberal, but not libertarian"... so in other words, in the early days libertarianism was not "classical liberalism" - it was explicitly opposed and quite distinct. For those libertarians, classical liberalism just wasn't good enough.
UPDATE 2: Jonathan Catalán shares his thoughts on Mankiw's post here, and seems to think that libertarian sympathies aren't compatable with "strict adherence" to Keynesianism.