Overview

Both the outer world of objects and events, and the inner world of our beliefs, are wired together by certain kinds of dependencies.

An external dependence: if one thing had not happened (my dropping the cup), then something else  wouldn’t have happened either (the cup breaking). An internal dependence: I believe that if it’s a weekday, then Harry will be in the library; hence whether or not I believe that Harry is in the library depends on whether or not I believe it’s a weekday.

In both the inner and outer worlds, conditionals (if-then statements) are the primary means of reporting these dependencies. And because the way that one thing depends on another is so central to both metaphysics and epistemology, the study of conditionals is a strategic issue at the core of philosophy.

This project investigates the metaphysics of conditionals—what features of the world determine when they are true? In particular, when the laws of the world are probabilistic, what makes counterfactual conditionals true? Relatedly, I critically examine how conditionals truths hang together: aspects of their logic. A key question for me is the scope and significance of situations in which conditionals are indeterminate.

I’ve recently been investigating the “Ramseyian” idea that all conditionals (counterfactual as well as indicative)  are indirect ways of reporting suppositional/hypothetical states of mind. Those suppositional states of mind are of key practical relevance since they play a central role in determining what actions are rational to perform. Conditionals, therefore, would allow us to articulate and examine our practical reasons in propositional form. But notoriously