On his return, after 1108, he found William lecturing at the hermitage of Saint-Victor, just outside the Île de la Cité, and there they once again became rivals, with Abelard challenging William over his theory of universals.
Sekembalinya, setelah tahun 1108, ia menemukan William menjadi pengajar di pertapaan Saint-Victor, di luar Île de la Cité; di sana mereka sekali lagi menjadi saingan, Abelardus menantang William melalui teori "universal"-nya.