Ennead IV.2 [4]: On the essence of the soul, II · 2

This is the deeper meaning of the profound passage (in the Timaeus), where we read "By blending the impartible, eternally unchanging essence with that in division among bodies, he produced a third form of essence partaking of both qualities."

Soul, therefore, is, in this definite sense, one and many; the Ideal-Form resident in body is many and one; bodies themselves are exclusively many; the Supreme is exclusively one.