 Parfit’s splitting persons shows that survival is a more important notion than identity when considering personhood (for a critical discussion see Gendler 2002a). We say they “show” such and such, but, “purport to show” might be better, since some of these thought experiments are quite contentious. What they have in common is that they aim to establish something positive. Unlike destructive thought experiments, they are not trying to demolish an existing theory, though they may do that in passing. In principle, given the fact that thought experiments can be rethought (see Bokulich 2001), and that the evidential significance is dependent on historical and local accomplishments (see McAllister 1996), it cannot be irrelevant to identify the intention of the thought experimenter, if one wants to determine the type of a thought experiment: “An imaginary experiment should be judged on its specific purpose” (Krimsky 1973, p. 331).