One of the most famous political quotes of the last half-century comes to us courtesy of Barry Goldwater, who in his 1964 GOP acceptance speech said, “Let me remind you that extremism in the defense of liberty is no vice. And let me also remind you that moderation in the pursuit of justice is no virtue.”

This quote has been on my mind of late, having been cited in a recent New York Times book review, in a National Affairs essay by Jonathan Rauch, and by my colleague Yuval Levin during a recent Heritage Foundation panel discussion he and I participated in. Levin said that many times in practical politics extremism in defense of liberty “is a vice. It is a very great vice. It is our vice.” That strikes me as quite right, and it’s important for conservatives to understand why it is right.

Before making my case, it’s important to acknowledge that we can all envision circumstances in which extreme measures can be justified. But they are rare, particularly in a republic like ours, where methods of persuasion are the usual (and much preferred) recourse. Nor would I deny that at certain points in our history extremists (like the abolitionists) made useful contributions to an important cause.

That said, my concern about those who endorse extremism is that it is by its very nature militant, a break with the kind of moderation that is essential for a free society. Extremism, of course, characterized the French Revolution, which (unlike the American Revolution) so unnerved Edmund Burke. It leads to dogmatism and distorted thinking, to viewing politics in apocalyptic terms.

Those who hold extreme views tend to favor immoderate, uncompromising, and even fanatical methods. It’s no wonder, then, that one of the antonyms of extremism is “conservative.” Extremism, therefore, cannot reliably serve the ends of conservatism–and using extremist measures to advance social stability and ordered liberty borders on being oxymoronic. Self-command, composure, and temperateness in the pursuit of justice can, in fact, be a virtue. And extremism in the defense of liberty can easily backfire.

All of which explains why I am a good deal more sympathetic to what Leo Strauss wrote in his essay Liberal Education and Responsibility (which can be found in this volume): “Moderation will protect us against the twin dangers of visionary expectations from politics and unmanly contempt for politics.”

To be sure, moderation itself is not enough to make politics meaningful. There is an indispensable role for those who are deeply committed to a cause, for passionate activists and polemicists. (For my part, no one could reasonably claim that I have not been critical, and at times harshly critical, of the current occupant of the Oval Office.) But Goldwater’s endorsement of extremism is, I think, a dangerous temptation for precisely the people who are most inclined to be active in politics. I would add that in America, as Goldwater himself found out, there has never been much of an appetite for extremism. Americans seem to have an instinctive aversion to it. Indeed, on the evidence of the American Revolution, they preferred that even their revolutionary leaders be, in the main, prudent, percipient, and judicious. James Madison was hardly anyone’s idea of a fanatic, nor are the Federalist Papers fierce and bellicose in either tone or substance.    

So at a time when more radical impulses seem to be making inroads in our politics, it seems to me to be important to reclaim conservatism, which recoils from extremism of any sort and from any side.