The increased birth-rate and increasing longevity has become, for many, the most difficult and critical question of our time. Every 70 years the world's population doubles, and no foreseeable advance in food production can match the expansion of human hunger. The lack of adequate foodstuffs has caused in the past-and will again- the crowded living conditions which spread disease, sudden famine whenever a needed crop fails, and the desire for lebensraum which results in war. Mr. Sax attempts to sum up every aspect of this ""demographic crisis"". He explores its historical origins in Malthus, and its religious and moral sources in the stand of the Catholic Church upon contraception. And he concludes that ""The world's greatest immediate need is a simple, effective, and inexpensive contraceptive."" Statistics argue the case forcefully, but rancor occasionally mars an otherwise sober polemic. Aims at a wide audience, but there have been several forerunners in this field of debate.