Canadian philosopher, mathematician. Pruss's philosophical thought reflects Christian orthodoxy. He is a Roman Catholic and a member of the Society of Christian Philosophers.
Pruss defends the principle of sufficient reason (PSR), claiming that it is self-evident, and arguing that the rejection of PSR creates problems in epistemology, modality, ethics, and even evolutionary theory.
Pruss is a critic of David Lewis's "extreme modal realism," and instead gives "a combined account" of Leibnizian and Aristotelian modality, which integrates the "this-worldly capacities" of the Aristotelian view and Leibniz's account of possible worlds as thoughts in the mind of God.