V. Whether the Soul is Simple or Compound.
We prove, then, that the soul is simple, best of all, by those arguments by which its incorporeality has been demonstrated. For if it is not a body, while every body is compound, and what is composite is made up of parts, and is consequently multiplex, the soul, on the other hand, being incorporeal, is simple; since thus it is both uncompounded and indivisible into parts.
Reproduced in full. Translation: Ante-Nicene Fathers, vol. 6 (Roberts and Donaldson, 1886), public domain (Public domain).