Note 13:1 — PART I. Pre-Islamic Persian Philosophy.
Reading edition
"If I see aright, five different conceptions can be distinguished for the period about 400 A.D. First we have the Manichaean which insinuated its way in the darkness, but was widely extended even among the clergy". (Harnack's History of Christian Dogma, Vol. V, p. 56). "From the anti-Manichaean controversy sprang the desire to conceive all God's attributes as identical i.e. the interest in the indivisibility of God", (Harnack's History of Christian Dogma, Vol V, p. 120).