These central questions are addressed and debated by the distinguished contributors to this lively book. Some of them—Hollis, Lukes, Robin Horton, and Ernest Gellner—discuss new directions in their thinking since their earlier articles appeared in 1970 in the seminal volume Rationality (edited by Bryan Wilson). They are now joined in the debate by Ian Hacking, W. Newton-Smith, Charles Taylor, Jon Elster, Dan Sperber, and, in the jointly authored lead article, by Barry Barnes and David Bloor.

Emerging from the debate are a variety of supportable interpretations and conclusions rather than a single, distinct "truth." The contributors represent the complete spectrum of positions between a relativism that challenges the very concept of a single world and the idea that there are ascertainable, objective universals.