Victor Albrecht von Haller was an 18th century scientist who did extensive work in the life sciences, including anatomy and physiology, botany, and developmental biology. His embryological work consisted of experiments in understanding the process of generation, and led him to adopt the model of preformationism called

Widely known as a key contributor to the Roman Catholic Church’s body of doctrine, St. Thomas Aquinas also published an opinion on the moral status of embryos and fetuses that seems contradictory to the