David published work in metaethics (where he defends a robust, non-naturalistic kind of moral realism), in the philosophy of law (where he criticizes some versions of "general jurisprudence", discusses moral and legal luck, and analyses the role of statistical evidence), in political philosophy (where he criticizes Rawlsian, public-reason liberalism, discusses false consciousness, and nudging), in ethics (where he discusses the status of hypothetical consent, and rejects the existence of moral luck), and more.