He also argued on the basis of Chalcedonian Christology, that because Christ retained his divine nature when he became man (the divine nature was added to the human nature rather than his human nature being made divine), the substance of the bread and wine remain the same rather than being changed into the substance of Christ's body and blood.
Ia juga berpendapat tentang dasar Kristologi Kalsedonia, bahwa karena Kristus mempertahankan alam ilahinya saat menjadi manusia (alam ilahi ditambahkan ke alam manusia ketimbang alam manusia-Nya menjadi ilahi), substansi roti dan anggur masih sama ketimbang berubah menjadi substansi tubuh dan darah Kristus.