This is a lively and wide-ranging collection of essays, drawn from the Herbert Spencer Lectures at Oxford University. Here, Peter N. Goodfellow, Germaine Greer, Sarah Blaffer Hrdy, Lucia Jacobs, Michele Le Doeuff, and Susan Cotts Watkins discuss current thinking on sex, gender, and gender and society. Topics include the socially constructed nature of gender, gender and rape, birth control in the developing world, information processing by men and women, sexual selection, and the interplay of fertility and literacy.