Scholastic opinion was yet another case of the scholastics following Aristotle too closely when it came to matters of science:
It was long debated among the learned at what period of gestation the human embryo begins to be animated by the rational, spiritual soul, which elevates man above all other species of the animal creation and survives the body to live forever. The keenest mind among the ancient philosophers, Aristotle, had conjectured that the future child was endowed at conception with a principle of only vegetative life, which was exchanged after a few days for an animal soul, and was not succeeded by a rational soul till later; his followers said on the fortieth day for a male, and the eightieth for a female, child. The authority of his great name and the want of definite knowledge to the contrary caused this theory to be generally accepted up to recent times. Yet, as early as the fourth century of the Christian era, St. Gregory of Nyssa had advocated the view which modern science has confirmed almost to a certainty, namely, that the same life principle quickens the organism from the first moment of its individual existence until its death (Eschbach, Disp. Phys., Disp., iii). Now it is at the very time of conception, or fecundation, that the embryo begins to live a distinct individual life. For life does not result from an organism when it has been built up, but the vital principle builds up the organism of its own body.
This is the strongest philosophical argument here. Human soul is the "vital principle" of the human organism and must be present to drive the growth. Human beings could not be alive or live and grow with just an animal soul driving the growth. That would be like saying the mother conceived a chimpanzee, and then had a soul infused into it to turn it into a human being. It must be considered a human being from the first moment of conception. [It reminds me of Pius XII's idea that God could have infused a soul into an evolved chimp ... shame on him for floating that out there.]
Topic: When Does Soul Enter Body? (Read 2966 times)