Thomas Aquinas' teachings which leant weight to heresy being an act of hubris, according to Aquinas "heretics were not to be tolerated but excommunicated and handed over to the civil power for execution" [Christie-Murray: 196, pg. 108]. ...
Another such theologian who shed some light into this debate was Thomas Aquinas (1225-1274 AD.). More than Augustine, Thomas was more concerned with the ontological status of the fetus in the early stages of pregnancy. ... Thomas held the delayed hominization view because of his hylomorphism, where the human soul is the form of the human being. ... Thomas's key point is that the final, the human, soul that comes from the outside is from God. ... It was assumed that, even though Thomas rare mentions abortion, he opposed to it on perversity grounds in more detailed examination. ...