Nor need this be wondered at if we consider that the unity of the human mind with the divine is its underlying presupposition.
In spite of some waverings towards what has lately been called " conditional immortality " (see Apologetics) the doctrine of " natural immortality " championed by Augustine became dominant in the church; an instalment of what was afterwards to be called Natural Theology; and a postulate or presupposition to-day - like free will - in Roman Catholic apologetics.
The systematic theosophy of Plotinus and his successors does not belong to the present article, except so far as it is the presupposition of their mysticism; but, inasmuch as the mysticism of the medieval Church is directly derived from Neoplatonism through the speculations of the pseudo-Dionysius, Neoplatonic mysticism fills an important section in any historical review of the subject.
It presents itself historically as an intellectual revolt against the difficulties involved in the presupposition of theistic and polytheistic systems, and in philosophy as an attempt to solve the dualism of the one and the many, unity and difference, thought and extension.
The idea of a perfect harmony of thinking and being is a presupposition that underlies all knowing but cannot itself be realized in knowledge.