It is a measure of the strength, clarity, and coherence of this outstanding book that the reader will sometimes be uncomfortable with its precise logic. Timothy Murphy, a professor of medical humanities at the University of Illinois College of Medicine at Chicago, builds a strong argument in support of sexual orientation research despite the fact that a scientific marker for sexual behavior would make possible a host of draconian bodily controls. These could include drug therapies and the selective abortion of fetuses marked by undesired sexuality. The possible reduction in the number of gay individuals that such science could conceivably produce is not a sufficient reason, in Murphy's interpretation, to constrain the choices of adults either to refuse to parent a gay child or to seek medical therapy themselves for their own unwanted desires.