Human Interests develops an ethical theory in the consequentialist tradition, but incorporating contractarian and deontological elements. Joseph Mendola argues that this theory is required by physical reality and the correct metaethics. Innovative features include a focus on group acts and on indeterminacies of morally relevant fact. It has three parts.

Part I is an account of our alternatives, of the objects of ethical evaluation. It defends an account of individual alternatives that is rooted in the conditional analysis of ability. It argues that our options incorporate objective ex ante probabilities but not lucky flukes. It develops a related conception of social alternatives. And it argues that in reality there is some indeterminacy of alternatives.

Part II propounds a way to morally evaluate alternatives. This ethical theory is supported by an account of the meaning of key moral terms. The theory includes an account of individual well-being rooted in actual preference satisfaction, an egalitarian principle for evaluating outcomes that reflects the limited comparability of different individuals' good, and a novel form of consequentialism based on group acts. Familiar competitor theories are shown to be either not viable in reality or reconciled in this view.

Part III applies the theories of Part I and II to deliver the most crucial commonsense moral judgments, and hence to answer standard objections to consequentialism. It develops accounts of our general deontological obligations not to lie, murder, injure, or steal, of our special obligations, and of the moral virtues. And it considers the demandingness of morality.