When Barack Obama says “ISIS is a perversion of Islam” he’s practicing rhetoric, not comparative religion.
“Does Obama love America?“Â and “Is Obama a Christian?“Â are both reflections of the same analytically absurd but politically potent winger theme song: “Obama doesn’t hate Muslims enough; he won’t say ‘Islamic terrorism.’ ”
Really, this gets much easier to understand if you recall that a President’s words are strategic choices rather than contributions to a seminar series. Strategically, it’s obvious that if you want some Muslims to help you fight other Muslims, then of course the last thing you want to do is define the common enemy as “Islamic.”
Even as a matter of pure analysis, there’s simply no true or false answer to the question: “Is ISIS an Islamic movement?” That question could mean either “Is ISIS an aspect of Islam?” -Â to which the answer is obviously “Yes” - or “Is the version of Islam adopted by ISIS the best or authentic version?” in which case the answer is equally obviously a matter of opinion or controversy rather than of ascertainable fact.
Consider the same analysis as applied to Christianity. Was burning heretics at the stake “Christian”? Well, of course it was, if by “Christian” you mean “Done by many Christians out of what they thought was loyalty to Christianity, and approved by many other Christians.” And of course it wasn’t, if you mean “Consistent with the views attributed to Jesus of Nazareth in the Gospels.” (See the Grand Inquisitor scene from the Brothers Karamazov.)
So the answer I ought to give to that question would depend on the context, the audience, and my purpose.
If I wanted to convince a Christian audience that persecution was wrong, then of course I would try to argue that burning at the stake was “un-Christian.” Since it’s certainly un-Christlike, I’d have a very solid basis for that argument. On the other hand, if I wanted to convince an audience of Buddhists or atheists that Christianity was evil, I’d want to argue that burning heretics at the stake, having been an uncontroversial part of actual Christian practice for more than 500 years, was mainstream Christianity, and that therefore the whole religion was manifestly the work of the Devil. Again, I’d have lots of evidence on my side.
The point is that “Christianity” names both an ideal of conduct (whose content is controversial)Â and an historical phenomenon with many strands, some of them mutually contradictory, and of course something that was an important part of the history could nonetheless violate some versions of the ideal.
Or take slavery or McCarthyism or the internment of the Japanese-American population during WWII. Were those phenomena “un-American”? Lincoln certainly thought so about slavery, which clearly contradicted the founding notion that “all men are created equal.” Â And almost no one now defends the politics of McCarthy or the policy of internment, which were far more reminiscent of Nazi or Communist purges and deportations than of law-guided republican politics.
But of course slavery was deeply entwined with our national history – being almost as old as English settlement in the New World and being protected, directly if euphemistically, by the Constitution itself – and McCarthyism and internment weren’t the only moments at which the paranoid strand in American politics got loose: Know-Nothingism and the Palmer Raids reflected the same craziness.
So, again, if I wanted to persuade Americans to live up to the best this country has to offer the world, I’d want to claim that slavery, internment, and McCarthyism were deeply un-American, and that getting rid of them helped move us toward “a more perfect Union.” If, on the other hand, I were an America-hater, or alternatively if I wanted to defend the use of torture, I’d want to insist that all those phenomena, like violence, were “as American as apple pie.”
There is no “truth of the matter” to be found in any of these cases, because neither “Christianity” nor “Americanism” has an empirically ascertainable “essence,” and because in each case the practice might differ substantially with from the ideal, and the ideal itself will certainly be a matter of controversy within the tradition. I can prove from the Gospels that pious cruelty is evil, and from the Declaration of Independence that slavery is evil; but I can’t deny that St. Dominic and John Calvin loved pious cruelty, or that the God of the Hebrew Bible explicitly commands it [Deut. 13:6-18], nor can I deny that the Constitution protected slavery.
As an interpretive historian or cultural critic, I might try to say something serious about the central tendencies of Christianity or of  the American tradition, but those arguments aren’t likely to be conclusive; if someone makes them as part of a political debate, he is practicing rhetoric rather than dialectic: trying to persuade, not merely to elucidate.
What’s absolutely certain is that if I want Christians or Americans to behave well, I shouldn’t criticize the bad behavior of some Christians or some Americans as typically -Â or even “extremely” - Christian or American; instead I should point out how inconsistent that behavior is with the best parts of those traditions.
This seems obvious. So why should “Islam” be different?
ISIS is recognizably “Islamic” in the sense that its leaders claim the mantle of Islam and its followers think they are good Muslims. Moreover, there is support in some Islamic texts – including the Koran – and traditions for some of ISIS’s bad actions. If I were an ISIS recruiter, of course I’d want to stress those links. And of course I’d do the same if I wanted to incite hatred against Islam or stir up a “holy war” between Christians and Muslims, or merely incite hatred against an American President with a Muslim name.
If, on the other hand, I wanted to convince an Islamic audience to join with me in fighting against ISIS, the last thing I’d do is describe that group as “Islamic extremists.”
Last time I checked, Barack Obama wasn’t elected to a chair of  cultural criticism or comparative religion; his profession is statesmanship, of which rhetoric is a fundamental tool. When he denounces ISIS as “a perversion of Islam,” he’s not making a claim for scholars to debate; he’s making a rhetorical move and offering a call to arms. Denunciations of his remarks from intellectuals as too one-sided and insufficiently nuanced, and by wingnuts and anti-Islamic bigots as insufficiently anti-ISIS, are equally beside the point.