The article aims to provide an introduction to one of the dimensions of Ronald Dworkin's political philosophy, his attempt to think the unity of political liberalism and of economic liberalism under the concept of equality. It sets out Dworkin's argumentation, from Taking Rights Seriously (1977) to Foundations of Liberal Equality (1990), while taking account of the articles on equality from 1981-1987. It is concerned more precisely to show how Dworkin, by progressively uncovering the moral foundation of the liberal ideal (of the system of fundamental freedoms, from constitutional democracy to the market economy), comes to define liberalism as a republicanism and can thus distinguish it clearly from both conservative and communitarian politi...