Most of these rituals take place during the first ten days of Muharram, reaching a climax on the tenth day, although majalis can also occur throughout the year.[122][124] Occasionally, especially in the past, some Sunni participation in majalis and processions has been observed.[125][126] According to Yitzhak Nakash, the rituals of Muharram have an "important" effect in the "invoking the memory of Karbala", as these help consolidate the collective identity and memory of the Shi'a community.[127] Anthropologist Michael Fischer states that commemoration of the Battle of Karbala by the Shi'a is not only the retelling of the story, but also presents them with "life models and norms of behavior" which are applicable to all aspects of life, which he calls the Karbala Paradigm.[128] According to Olmo Gölz, the Karbala Paradigm provide Shi'as with heroic norms and a martyr ethos, and represents an embodiment of the battle between good and evil, justice and injustice.[129] Rituals involving self-flagellation have been criticized by many Shia scholars as they are considered to be innovative practices damaging reputation of Shi'ism.