Last week, a psychotic anti-multiculturalism, anti-immigrant, anti-Marxist named Anders Behring Breivik shot up a children's summer camp in Norway. The left wing media was only too eager to point to his ideology as the rationale for the shooting. David Neiwert of CrooksandLiars.com stated that Breivik subscribed to the "theories about 'Cultural Marxism' ... promoted by the likes of Andrew Breitbart, among others." The Daily Kos tried to link Breivik to Accuracy in Academia and the World Congress of Families. Think Progress blamed Frank Gaffney of the Center for Security Policy, blogger Pamela Geller, author Brigitte Gabriel and scholar of Islam Robert Spencer. In short, it was a repeat of the Sarah Palin-Gabby Giffords story, only writ large.
This begs the question: when should an ideology be held responsible for murder undertaken by its adherents?
The quickest answer -- when an adherent of an ideology commits murder, the murderer is responsible -- is obviously the wrong one. Adherents of every ideology commit murder on a regular basis. They may be doing so because they misinterpret the ideology or because they are insane.
A more rational answer would require an ideology to fulfill two basic criteria in order to be blamed for a particular act of violence. First, the ideology must itself promote the sort of violence at issue and the type of violence that takes place must bear some resemblance to the violence being promoted. This makes sense. If a group of pacifists shot-up a school, we could say with accuracy that they'd clearly misinterpreted pacifism. The same does not hold true of neo-Nazi ideology and Jews.
Second, a large number of adherents to the ideology must engage in or support the form of violence in question. It is possible for formerly violent ideologies to change over time -- no one, for example, save Timothy McVeigh, thinks that Constitutional ideology is violent anymore, despite Thomas Jefferson's proclamations about the tree of liberty and the blood of patriots.
Let's take a test case, Islam. There is no question that Islamic texts promote violence against Jews and Christians. For example: the Koran famously proclaims, "Slay the idolaters wherever ye find them, and take them captive, and besiege them, and prepare for them each ambush." With regard to Jews, one famous tidbit of Islamic oral tradition delightfully states, "The Day of Resurrection will not arrive until the Moslems make war against the Jews and kill them, and until a Jew is hiding behind a rock and tree, and the rock and tree say, 'Oh Moslem, oh servant of Allah, there is a Jew behind me, come and kill him!'"