Aristotle held that equals should be treated equally and unequals unequally. Yet Aristotle's ideal of equality was a relatively formal one that allowed for considerable inequality. Likewise, Thomas Hobbes, John Locke, and Jean-Jacques Rousseau all maintained that the equality in the state of nature could be reconciled with significant inequalities in social life. Immanuel Kant too held a view that justified considerable inequalities. In the nineteenth and twentieth centuries, however, more substantive ideals of equality, including ideals of economic and social equality, began to be defended by socialists, Marxists, welfare liberals, and feminists alike. As a result, the compatibility of the political ideals of liberty and equality has been seriously brought into question: how could such substantive ideals of equality be reconciled with an ideal of liberty?

Some contemporary political philosophers have sought to resolve the apparent conflict by simply endorsing an ideal of positive rather than negative liberty – one that can clearly be seen to impose the same requirements as a substantive ideal of equality. But this strategy simply begs the question unless we can demonstrate the moral or rational superiority of an ideal of positive liberty in the first place, which seems very difficult, if not impossible, to do.

In this book, Jan Narveson will argue for the incompatibility of the political ideals of liberty and equality, while James P. Sterba will argue for their compatibility.