Argument for the Reasonableness of Eucharistic Substantiation


  • Jesus is fully God and fully man (J == G && M)
  • ‘to be’ is a substantial statement ('==' = substantial)
  • Jesus’ substance is fully the substance of God and fully the substance of man (s(J) == s(G) && s(M))
  • The substance of God is immaterial (s(G) = i)
  • The substance of man is material (s(M) = m)
  • So, the substance of Jesus is fully material and fully immaterial (s(J) == i && m)
  • Therefore, some substances can be be fully material and fully immaterial (V s == i && m)

I am sure that someone could poke holes in the logic of that argument–and I welcome any such comments; however, I also currently find it convincing. Given the conclusion, then, I simply ask myself: “Is it likely that the Eucharist is a member of the set of possible substances that can be both fully material and fully immaterial?” To my mind, it is likely. When Jesus says “this is my body” and “this is my blood”, these are terms of a substantial register. Moreover, these are statements of identity (using the verb “to be”). Finally, for me, the parallelism of Jesus is to God and man as eucharistic bread is to Christ’s body and regular bread fits too well into the general structures of Christian thinking.

In short, I believe both that consubstantiation is reasonable and true.