Mathematics

Ethics involves complicated problems that overlap with formal epistemology, philosophy of probability, decision theory, and game theory. No one could deny the relevance of mathematics to those subjects, so it would be remarkable if mathematical methods were not central to the study of ethics.

My own work especially involves axiomatic methods. Ordinary language is not well suited to the precise statement of axioms, and it is almost impossible to work out the consequences of even small sets of simple axioms without some mathematics.