Although democratic and liberal societies proscribe the use of violence to promote political ideas, political violence is considered by some groups as a manner of doing politics in a different way. We conducted a qualitative sociological survey among French far left groups. In their discourse, we identified four grammars of legitimation of political violence used by these political groups. This research contributes to knowledge concerning the dual grammar of instrumental vs. normative legitimations of political violence (see Sommier, 2008). It also broadens knowledge of the “techniques of neutralization” described by Sykes and Matza (1957) in their study of deviance.