G. E. R. Lloyd explores the variety of ideas and assumptions that humans have entertained concerning three main topics: being, or what there is; humanity—what makes a human being a human; and understanding, both of the world and of one another. Amazingly diverse views have been held on these issues by different individuals and collectivities in both ancient and modern times. Lloyd juxtaposes the evidence available from ethnography and from the study of ancient societies, both to describe that diversity and to investigate the problems it poses. Many of the ideas in question are deeply puzzling, even paradoxical, to the point where they have often been described as irrational or frankly unintelligible. Many implicate fundamental moral issues and value judgements, where again we may seem to be faced with an impossible task in attempting to arrive at a fair-minded evaluation. How far does it seem that we are all the prisoners of the conceptual systems of the collectivities to which we happen to belong? To what extent and in what circumstances is it possible to challenge the basic concepts of such systems? examines these questions cross-culturally and seeks to draw out the implications for the revisability of some of our habitual assumptions concerning such topics as ontology, morality, nature, relativism, incommensurability, the philosophy of language, and the pragmatics of communication.