 The motivations for making an exception for organisms vary. Van Inwagen (1990: Ch. 12) accepts organicism on the grounds that it yields the best answer to the special composition question (“under what conditions do some objects compose something?”), one that allows for one’s own existence and physicality, while at the same time escaping various problems that arise for competing answers. Merricks (2001: Ch. 4) argues that persons and some other composites must be recognized on account of their nonredundant causal powers. Making such exceptions naturally gives rise to concerns about the stability of the resulting positions, either because the reasoning behind allowing the exceptions threatens to generalize to all ordinary objects or because the arguments for eliminating ordinary objects threaten to generalize to the objects one wishes to  permit.[5]