Thomas Fienus, a physician and a professor in the University of Louvain, in 1620 published a book[25] in which he held that the soul is infused about the third day after conception, and his argument for the early advent of the soul is very sound. As a result of Fienus's revolutionary argument, Florentinus in 1658 brought out a book at Lyons, called _De Hominibus Dubiis Baptizandis_, in which he held that no matter what the age of the aborted fetus, if it could be differentiated from a mole it should be baptized. This book was brought before the Congregation of the Index. The congregation did not condemn the book, but the author was forbidden to teach that his doctrine holds _sub gravi_. The book went through many editions and was approved by the faculties of the principal universities and the theologians of the leading religious orders. [25] _De Vi Formatrice Foetus Liber._ Zacchias, chief physician to Innocent X., in 1661 published his _Questiones Medico-Legales_, and in this he maintained that "the human fetus has not at any time any kind of soul other than a rational, and this is created by God at the first moment of conception, and is then infused."[26] By 1745 the opinion of Zacchias as to the moment life begins was virtually general among physicians, and has since remained the doctrine of physicists. Modern discoveries by biologists have confirmed the fact that human life exists in the impregnated ovum exactly as it does in all stages of life, and no scientist holds any other opinion. There are, however, a few moralists at the present day who incline to the old Thomistic doctrine or to modifications of it. [26] Tom. ii, lib. ix, tr. 1.