This book pursues two goals in the context of resurgence of interest in "the common good" as a topic in political philosophy and Christian ethics. The first goal is the clarification of the notion of common good, elaborating it through the three lenses of Aristotelian practical philosophy, twentieth century Catholic Social Thought, and political liberalism. The second goal is to make the case that the espousal of the common good does not entail a rejection of liberalism, but that a commitment to liberal politics is compatible with faithful adherence to the Catholic tradition. The first goal is warranted by the fact that many authors such as Michael Sandel who invoke "the common good" do not explain the concept. The second is necessitated by the tendency among many contemporary Catholic authors to polarize liberalism and the common good, presenting readers with a stark choice. Instead of exacerbating divisions this book explores what is common, even where there is difference and division. The Second Vatican Council's Gaudium et spes invites all to a dialogue about the common good as the set of economic, political, legal, and cultural conditions for the flourishing of human beings, whether as individuals or as communities. The challenge of dialogue is taken up through the three lenses, identifying a heuristic concept of the common good, along with two criteria for its application. First, no systematic exclusion of any person or group, and second, no systematic exclusion of any genuine dimension of the human good. These criteria have their counterparts in the principles of solidarity and subsidiarity. They prove their usefulness in discussion of democracy, human rights, and religious liberty, accepting a political liberalism that can facilitate the collaboration in political life by exponents of many different worldviews and religious doctrines"--