My sympathies as a fellow academic lie with Mann. And yet, as a believer in the First Amendment, I am troubled. I would rather that name-calling weren’t a regular part of our public debate, but it is. Indeed, I should note for the uninitiated that “molested and tortured data” is the sort of molested and tortured prose that academics commonly inflict on each other (and the great unwashed beyond the campus) in this unenlightened era of discourse.

I myself have been accused from time to time of lying about the evidence or reasons for my views on a variety of subjects. Ad-hominem charges have no legitimate place in the academy — always be wary of the scholar who attributes motive to another! — but I’m uneasy at the thought that even so scurrilous a claim should be actionable.

Of course we need defamation law. But our constitutional tradition correctly makes it difficult for public figures to prevail. Close cases should go to the critic, no matter how nasty or uninformed. The preservation of robust dissent allows no other result, and robust dissent is at the heart of what it means to be America.

I am old-fashioned enough to believe that the cure for bad speech is good speech.