This article examines the strategy adopted by French philosopher Jacuqes Maritain (1882-1973) when he argued against claims made during the Spanish Civil War that the Nationalists were waging a "holy war" in defense of Catholicism in Spain. His critique of this religious ideology was two-pronged. On the one hand he explained how the violent methods employed by the Nationalists were wholly incompatible with action that might be deemed "holy". Hence, to speak of a "holy war" in this context was an unacceptable oxymoron. On the other hand, setting his argumentation within a philosophy of history, Maritain elucidates that while the idea of holy war might have had a basis within the "sacral" conception of the temporal that was prevalent during the European Middle Ages, within the "secular" conception of the temporal that is characteristic of European modernity, this idea no longer enjoys any possible validity. Hence, appeals to "holy war" in the Spanish context of the 1930s reflected a dangerous anachronism that should henceforth be recognized as illegitimate within Christian discourse.