Transmission and Survival of Iberian Patristic Texts (3rd–5th Centuries)

This paper analyses the textual transmission of the Church Fathers from the Iberian Peninsula. The corpus is characterised by formal (prose, verse) and generic (sermons, letters, chronicles, epics) heterogeneity. Our computational analyses reveal two contrasting transmission dynamics: prose texts are more numerous but are transmitted by fewer witnesses, sometimes only via their inclusion in medieval collections. Poetic texts, fewer in number, have generated a higher number of witnesses, likely due to their integration in large literary projects. We model these dynamics using two approaches: probabilistic unseen species models, which estimate an upper bound of text and witness survival rates and indicate low corpus diversity and evenness; and stochastic birth-death models, which explore cultural evolutionary patterns in text and witness populations. Results suggest a text survival rate below 67% (potentially closer to 20%) and a manuscript survival rate below 10% (possibly under 1%). Notably, these estimates diverge from prior findings for Medieval French literature, where unseen species and birth-death models yielded similar results. This discrepancy suggests that diachrony – specifically, the broader chronological range of the patristic corpus – plays a key role in shaping transmission outcomes. Our findings also highlight limitations of the birth-death model, particularly in accounting for highly successful texts and in temporal variations in production/destruction rates.