This innovative history of welfare economics challenges the view that welfare economics can be discussed without taking ethical values into account. Whatever their theoretical commitments, when economists have considered practical problems relating to public policy, they have adopted a wider range of ethical values, whether equality, justice, freedom, or democracy. Even canonical authors in the history of welfare economics are shown to have adopted ethical positions different from those with which they are commonly associated. Welfare Theory, Public Action, and Ethical Values explores the reasons and implications of this, drawing on concepts of welfarism and non-welfarism developed in modern welfare economics. The authors exemplify how economic theory, public affairs and political philosophy interact, challenging the status quo in order to push economists and historians to reconsider the nature and meaning of welfare economics.