 Genuine causal overdeterminants occur when two or more causes both occur and each is sufficient to generate a particular effect. For example, perhaps a table has five legs, four at the corners and one at the center. It may be the case that the four legs at the corners are sufficient to cause the table to remain upright, but if the four legs at the corners were removed, the center leg would also be sufficient to keep the table upright. Here, the effect of the table’s remaining upright is overdetermined by the center leg, on the one hand, and the four legs at the corners, on the other. Similarly, perhaps a person has two good reasons for holding a belief, and either one alone would be sufficient to cause the belief. In this case, the two reasons would be said to overdetermine the belief. Assuming that the causal relations were not deviant, the belief would be based on both of the reasons. The ‘ri’ and ‘rj’ in (DB) are simply reasons on which the belief is based. Condition (ii) allows that a reason rj, which is in turn a reason for ri, which in turn is a reason for the belief that h, is also a reason on which the belief that h is based, and the “or …, etc.” clause is intended to include each of the reasons in a long chain of reasoning leading to the belief to count as reasons upon which the belief is based.