Some later medieval theories of the Eucharist : Thomas Aquinas, Gilles of Rome, Duns Scotus, and William Ockham

How can the Body and Blood of Christ, without ever leaving heaven, come to be really present on eucharistic altars where the bread and wine still seem to be? Marilyn McCord Adams examines how this question and its answer ("transubstantiation") engaged thirteenth and fourteenth century philosophical theologians.