Debates about personal identity relate to haecceitism in diverse and complex ways. Perhaps most notably, some arguments for the “Simple View” of personal identity (alternatively, the “Further Fact view”), according to which facts about the identity of persons over time are irreducible and non-qualitative, are plausibly taken as arguments for haecceitism. (On anti-reductionism and the Simple View, see Parfit (1984: 210) and Olson (2012).) These arguments exploit so-called “fission cases”, which involve an individual that apparently splits into distinct individuals but without principled grounds for identifying one rather than another of the post-fission individuals with the pre-fission individual. According to some proponents of the Simple View, it seems possible that that the pre-fission individual be identical to one of the post-fission individuals while, in other physically and psychologically indiscernible worlds, the pre-fission individual is identical to an apparently different post-fission individual. If, however, these are each genuine possibilities, facts about the identity of persons over time do not supervene upon any physical or psychological facts. And, since these are the qualitative facts typically held to be relevant to personal identity over time, such cases suggest that facts about personal identity over time do not supervene upon qualitative features. In this way, the Simple View lends support to the more general thesis that non-qualitative facts about the identity of persons do not supervene upon qualitative facts.