Following the account of names he found in classical works on grammar, Roscelin assumed that if the divine Persons have three different names, they must be not one, but three “things.” Abelard attacked this assumption, turning against Roscelin his own strategy of distinguishing the level of words from the level of things. The Persons cannot be different things, as Roscelin claimed. That would be to fall into the heresy of tritheism: a belief in three gods
