Xavi Lanao

Traditionally, philosophers have cashed out the distinction between law-like and accidental regularities sharply: a regularity is either law-like, and thereby necessary, or accidental. However, Mitchell and Lange have drawn attention to the fact that some law-like regularities come in different degrees of necessity. For instance, the regularity expressed by “all electrons are negatively charged” has a greater degree of necessity than the one expressed by “all mammals are warm-blooded”, even if both of them are true. Moreover, Mitchell argues that the dichotomy between accidental and necessary regularities is unable to capture the complexity of the causal structure of the world. Building on this, I argue that regularities do not only come in different degrees of necessity, but also have different formal features and ontological features. All these features matter in order to make sense of the causal complexity of the world. Accordingly, I propose a new conceptual framework to analyze regularities according to three mutually independent levels of analysis: formal features, degree of necessity, and ontological grounds. This new framework can make sense of different degrees of necessity, and it naturally accommodates a wide variety of scientifically-relevant regularities including those typically associated with laws of nature, biological mechanisms, and dispositional properties.

How we define the space of possibilities of dispositional essentialism —that is, the set of possible worlds that are genuinely possible from the point of view of DE—has important consequences for central modal debates such as how to understand the concept of essence or the relation between DE and the necessity of laws of nature. In order to define DE’s space of possibilities we need to explore DE’s consequences regarding both necessity and possibility. Unfortunately, the notion of possibility has not received much attention within the DE literature. In this paper, I attempt to fill this gap. I argue that the standard way of understanding possibility found in the literature—a proposition is possible iff it expresses the manifestation of some actual disposition—needlessly restricts the space of possibilities by not accepting global and absolute possibilities, including some alien properties, as genuinely possible. I propose instead to accept a more permissive understanding of possibility: a proposition is possible iff it does not contradict any of the necessities that follow from the core commitments of DE. This allows dispositionalists to expand their modal space and to account for modal intuitions that may otherwise undermine the tenability of DE.