 For example, animalists often ally their answer to the persistence question with Locke’s identity criteria for human animals (e.g., Olson 2007: 28). Of course, since organic animalists affirm and somatic animalists deny that being alive is a necessary condition of our persistence, Locke cannot be an ally to both camps. For his part, D. Mackie (1999b: 235–39) classifies Locke as an organicist. However, enough passages from the Essay suggest otherwise (some of which Mackie himself acknowledges—e.g., in II.xxvii.4–5) that the more circumspect conclusion may be that Locke was either inconsistent or just ambivalent on the matter. Animalists are also sympathetic to Locke’s account of personhood—albeit with a different understanding of the type of concept person is—and this alternative understanding allows animalists to endorse element (d) above.