Tom Kirkwood, Professor of Medicine and head of the Department of Gerontology at the University of Newcastle presents the third of five Reith Lectures investigating new insights from the frontiers of science and the choices and decisions we face in the uncharted territories of a greying world.

In this lecture Professor Kirkwood tackles the subject of sex. Does sex shorten our lives? Can it be, as some have suggested, that ageing and death are the price we pay for sex? Does it make sense to think in terms of a 'reproductive duty' to the species, leaving us surplus to requirement when duty is done? And what, if these worrying notions are true, are we to make of the post-menopausal woman? These are the questions he examines; revealing that the answers are not only reassuring, (on the whole), but also, that they tell us a great deal about the biological background to our revolution in longevity.