Late Medieval anti-Jewish violence is a well-known phenomenon, but its origins and institutionalization are still blurred and enigmatic. In thirteenth and fourteenth century Catalonia, the denouement of the increasing popular hostility against the Jewry was particularly dramatic. The seeds of violence were the result of a long and complex process of social, theological and political interactions. In this contribution, we will discuss the intellectual matrix of medieval anti-Semitism in Catalonia and its relationship with the rising of scholastics and with the theoretical foundations of Catalan politics. We will also approach its counterpart: the Jewish response to collective suffering.