Explanatory Chance

Debates in philosophy of probability over the nature and ontology of objective chance by and large remain inconclusive. No reductive account of chance has ultimately prospered. This article proposes a change of focus towards the functions and roles that chance plays in our cognitive practices. Its starting philosophical point is pluralism about objective probability. The complex nexus of chance is the interlinked set of roles in modelling practice of i) parametrized probabilistic dispositions (“propensities”); ii) distribution functions (“probabilities”); and iii) statistical finite data (“frequencies”). It is argued that the modelling literature contains sophisticated applications of the chance nexus to both deterministic and indeterministic phenomena. These applications may be described as lying on a spectrum between what I call ‘pure probabilistic’, and ‘pure stochastic’ models. The former may be found in the tradition of the method of arbitrary functions; the latter in present-day techniques for stochastic modelling in the complex sciences, as well as some orthodox approaches to quantum mechanics. These modelling practices provide positive arguments for the irreducible complexity of the chance nexus