In the short, turbulent history of AIDS research and treatment, the boundaries between scientist insiders and lay outsiders have been crisscrossed to a degree never before seen in medical history. Steven Epstein's astute and readable investigation focuses on the critical question of "how certainty is constructed or deconstructed," leading us through the views of medical researchers, activists, policy makers, and others to discover how knowledge about AIDS emerges out of what he calls "credibility struggles."

Epstein shows the extent to which AIDS research has been a social and political...