Alain Boureau, Heredity, Errors and Truth of Human Nature (12th-13th Centuries)

The article explores the place of heredity and the possibility of a lower order of humanity in 12th and 13th century Christian anthropology, by studying the notion of the ‘truth of human nature’. In order to remove the last traces of traducianism, several 12th century theologians, such as Peter Lombard, adopted a physical and physiological approach to the hereditary transmission of original sin. This led them to affirm a specific status for the part of our body inherited from our parents and from Adam. This human nature, transmitted from generation to generation, is imper- vious to the influence of food and it is this nature that will be resurrected. However, in the 13th century, the masters of theology strongly rejected the idea that food does not enter the truth of human nature.They also treated the theme in a progressively naturalistic manner, mainly by using the medical concept of ‘radical moisture’. Two tendencies appeared. Thomas Aquinas described the truth of human nature essentially in terms of the individual, as the composition of body and soul, thus obviating the issue of the material continuity and homogeneity of human nature whilst, at the same time, taking the view that inherited flesh and flesh developed from nourishment form a perfect mixture. Peter of John Olivi, a major representative of the Franciscan tradition, accepted the contribution of food to human nature, but also maintained a certain distinction between the two kinds of flesh. Here, the part of the inborn remained more independent, even though in both views, the part of the original structure became less and the role of the acquired part became greater. Beyond the differences in ideas, the 13th century relativised the idea of human nature and thus opened up the possibility of variations of the norm of the human. However, the implications of this evolution of ideas remained virtual with respect to the central idea of the universality and permanence of the transmission of original sin, which impeded thought on the transmission of specific markers among various human groups.