ABSTRACT
This chapter begins with a description of part of the mechanism of bacterial chemotaxis and makes some general remarks about roles for probability in mechanisms. Under metaphysics, it includes a brief general discussion of interpretations of probability, and argues that those interpretations of probability relevant to the functioning of mechanisms are usually causal probability interpretations. Despite the diversity of mechanisms in the world, their character and the way in which they are studied generally places constraints on what interpretations of probability are suitable as analyses of activity probabilities. The chapter considers a kind of systematicity intermediate between causal probability and pure erraticity. It suggests that some stochasticity in mechanisms might not involve probabilities per se, but could instead involve what are known as imprecise probabilities. The chapter also discusses various strategies for modeling probabilistic mechanisms, as well as evidence for probabilities in mechanisms. It concludes with a discussion of non-recurrent mechanisms.
