‘God kan net doen wat God wel doen’: Petrus Abelardus se Megariaanse argument in Theologia ‘Scholarium’, Opera Theologica III

‘God can only do what God does do’: Peter Abelard’s Megarian argument in Theologia ‘Scholarium’, Opera Theologica III Peter Abelard’s contribution to a constellation of central themes in post-Carolingian medieval philosophy, namely on causation, necessity and contingency, with its discursive undertone of the relation between potentiality and actuality, is worked out in a rather informal way in one of his later works, Theologia ‘Scholarium’. Typical of the fusion of philosophical questions and theological premises in medieval philosophy, Abelard addresses the issue by asking whether God can only do what God does. Abelard argues that God can do or not do or omit doing only those things which God does do or does not do or omits doing and that God can do or can not do or omit doing those things only in the way or at the time at which God does and not at any other. Given Abelard’s fragmented and restricted access to the Aristotelian corpus regarding causality, how did he come to this Aristotelian-orientated conclusion? This article stresses the ancient quality of Abelard’s argument from another angle, reminiscent of the so-called Master Argument of the Megarians, with specific reference to the dialectical legacy of Diodorus Cronus, according to whom what can be is what is: what is, in turn, is what must be. Actuality, for the Megarians, exhausts potentiality. The path of actuality cannot be undermined or compromised by issues of potentiality. God’s actions are thus for both the Megarians and Abelard strictly determined and determining. God, in the end, can only do what God does. This article contributes to scholarship in medieval philosophy or theology by making this connection explicit and by thoroughly exploring the link between Abelard and his ancient predecessors.