The Dominican theologian Albert the Great (c. 1193-1280) devotes several pages to investigating the dynamics involved in the configuration of the embryo. In the 13^th century, ‘embryology’ as a specific branch of biology did not exist, and the study of the configuration of the living being was the prerogative of physicians as much as of theologians. The embryological discourse was the place of confluence between different fields of knowledge. Natural philosophy and medicine explained embryonic formation as a progressive development of bodily and psychic functions. This explicative model, however, was at variance with the theological assumption that only God infuses the rational soul into the embryo when its body is fully configured. What is, thus, responsible for the dynamics of the configuration of the embryo before its ensoulment?

Albert the Great stands out among the 13th-century Latin authors for his attempt to answer these questions through an interdisciplinary approach that intertwines medical, natural-philosophical, and theological concerns. [1] This approach is strictly connected to Albert’s intellectual endeavour as magister theologiae at Cologne. In 1248, the Dominican Order entrusted Albert with the foundation and organization of the Studium generale (i.e., a university for Dominican friars). Thus, he modelled the curriculum studiorum after the Aristotelian corpus, updated and receptive to the philosophical debates of the time. He was convinced that Dominican friars should be versed in theological disciplines and liberal arts. In such a framework, for the benefit of his Dominican students, he commented on the entire Aristotelian corpus. [2]

Far from being purely Aristotelian, in his philosophical commentaries, Albert takes the opportunity to criticize and question Peripatetic doctrines, allowing his theoretical standpoint to emerge more or less explicitly. [3]  Through amplifications, glosses, and digressions, he makes room for his personal reformulation of the natural-philosophical, medical, and theological doctrines on embryogenesis available in the 13^th century. [4]

The core tenet of Albert’s embryology is the virtus formativa, i.e, formative power, a shaping force responsible for crucial dynamics in the configuration of the living being. [5] In the 13^th century, this notion was ascribed to Galen, whose medical thought was acquainted through the mediation of Arabic philosophers and physicians. [6] It was mainly from Avicenna’s work that Albert drew information on Galenism and its discrepancies with the Aristotelian natural philosophy.

Albert focuses on the dynamics of the configuration of the embryo, explaining how the morphological and functional structures are handed down from parent to child without presupposing the transmission of the soul.

In the generative process, parents transmit to the offspring not a soul but a likeness of the bodily powers and functions of the soul of which the virtus formativa is both vicar and carrier. This power, though, does not evolve in the embryo’s soul. It acts just before the soul reception as the principle of organization and configuration of the body.

The formative power is conveyed by the seed which virtually acquires morphology, function, and accidental traits from the generating body. To prevent any possible preformist interpretation of the formative power of the seed, Albert claims that this power does not contain latently bodily shapes and powers but is just the principle of the embryo’s morphogenesis. [7] Once in the embryo, the virtus formativa is localized in the heart, from which it starts the material realization based on the bodily design acquired from both parents.