 By contrast to this “actualism”—the conception that reduces possibility to actuality (see Bueno 2014)—some modal interpretations, in particular MHI, adopt a possibilist conception, according to which possible events—possibilia—constitute a basic ontological category (see Menzel 2018). The probability measure is in this case seen as a representation of an ontological propensity of a possible quantum event to become actual (Suárez 2004; Terekhovich 2019  [Other Internet Resources]).