Simon Magus functioned as the typological archetype of all later heresy

Evidence

Isidore is well aware of the variety of Christian heresy; indeed, he lists dozens of heresies and heresiarchs in Etymologies 8. Yet Simon, for Isidore as for many medieval writers, is the father of heresy: a model whose errors later heresiarchs will typologically reenact, just as saints typologically reenact the deeds of Christ and the apostles. — John V. Tolan, Saracens, 133

Categorization

• DEFINE: Clarifies the heresiological typological mode through which medieval authors viewed error — the template later applied to Muhammad and Islam.