The most clarifying test cases for free speech involve the defense of the vile.

Conversely, free speech contests over works that may have intellectual artistic merit inevitably become muddled in side issues of cogency and aesthetics.

As an example of the latter, the PEN American Center created controversy by bestowing the Freedom of Expression Courage Award to French weekly Charlie Hebdo, for “paying the ultimate price for the exercise of their freedom, and then soldiering on amid devastating loss.” Supporters of the award celebrated Hebdo’s irreverence, while opponents claimed the magazine was racist and Islamophobic. Yet the case became a debate about the merits of Hebdo's satire, overshadowing the core issue of defending free speech—and the crucial question of the motive for the attacks on Hebdo and how best to respond to them.

The attempted attack Sunday on a “Muhammad Art Exhibit and Cartoon Contest” in Garland, Texas, which left a policeman injured and two gunmen dead, is an example of a clarifying event. Unlike Hebdo, it’s difficult to find either intellectual or artistic merit in the offending works (see the prize winner here). The event was organized by American Freedom Defense Initiative, whose executive director, Pamela Geller, is a notorious Islamaphobic hatemonger known for allying with European neo-fascist parties. In a typical blog post from 2010, Geller refers to Barack Obama as “Hussein,” and says the president “is a muhammadan. He's not insane… he wants jihad to win.”

It’s precisely because Geller is so heinous a figure that free speech issues come into sharp relief. Geller is a far-right provocateur, but she has every right to express herself in any way she wants, short of incitement to violence. The provocative nature of her many anti-Islamic comments in no way excuses the attacks on the exhibit. The gunmen, and those who incited them, bear sole responsibility for the crime.