Abstract
Such is the rhetorical appeal of the idea of liberty that a variety of political philosophies claim to honour it. Republicans and Marxists, no less than libertarians and liberals, maintain that they and they alone are the true defenders of freedom. The literature of contemporary political theory is thus replete with rival analyses of the meaning of liberty, and disputes about its measurement, distribution and institutional requirements. Our aim here is to gain some understanding of the meaning and the conditions of liberty by working through the thicket of contemporary argument, though we may have to rest content with a better knowledge of the terrain.