[Compare On the City of God, xiv. 2, 6, and On the Trinity, x. 11, 18. Augustin denied the trichotomy of the Greek Fathers before Appollinaris, and held that the soul and spirit constituted a single substantial unity, and this one spiritual essence was “soul” (anima) so far as it was the informing and vivifying principle of the body, and “spirit” (spiritus) so far as it was the power of rational thought.—W.]