Justice and Equity is a major work on the foundations of normative economics. The principles established by Kolm have formed the basis of the major lines of study in the field. The central principles are the ideal equalities in freedom (related to non-envy) and in happiness (approximated by the efficient leximin in fundamental utility). Kolm also presents related principles such as fundamental dominance and majorities, realistic equity, and adequacies. He analyzes thoroughly the reasons, properties, and consequences of these principles. A foreword for the English-language edition presents the rational necessity of equality and the theory of interpersonal comparisons.