In recent years the traditional position of the Catholic Church on contraception has come under attack even from otherwise loyal Catholics who question the grounds in the light of demands of modern living and scientific advances in the area. There has been a flood of books -- almost all arguing for a review of the Church's position. Professor Crises here comes to the defense of the Church's stand. The approach is philosophical but only Catholics who will accept his premises will be convinced by the total case. He insists that contraception is intrinsically immoral and that rhythm is sound and the only answer for people today. Though he offers documentation of his thesis, his presentation is dogmatic. Nevertheless it is well that this side of the picture has been given exposure. Priests, bisheps and laity will be interested in this case of the Catholic position especially since it is from a relatively non-religious, objective point of view. That a is layman offers this argument makes it particularly timely and in keeping with the new openness of the Church.