Alan Thomas presents an original study of the status of value and its relation to the contexts in which evaluative claims are justified. He articulates and defends the view that human beings do possess moral and political knowledge, but that it is historically and culturally contextual knowledge in ways that, say, mathematical or chemical knowledge is not. His exposition of a 'cognitivist contextualism' in ethics and politics builds upon contemporary work in epistemology, moral philosophy, and political theory to fashion an argument that is relevant to current debates about culture, modernity, and relativism.