Almost every country today contains adherents of different religions and different secular conceptions of the good life. Is there any alternative to a power struggle among them, leading most probably to either civil war or oppression? The argument of this book is that justice as impartiality offers a solution. According to the theory of justice as impartiality, principles of justice are those principles that provide a reasonable basis for the unforced assent of those subject to them. The object of this book is to set out the theory, explain its rationale, and respond to the variety of criticisms that have been made of it. This is the second volume of A Treatise on Social Justice. The first, Theories of Justice, explored alternative theories and concluded by asserting the superiority of justice as impartiality. This conclusion is built on in Justoce as Impartiality, but it does not presuppose acquaintance with Theories of Justice.