Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Manichæan Controversy.: Chapter 17

Chapter 17.—The Memory Contains the Ideas of Places of the Greatest Size.

Again, if we consider the mind’s power of remembering not the objects of the intellect, but material objects, such as we see brutes also remembering (for cattle find their way without mistake in familiar places, and animals return to their cribs, and dogs recognize the persons of their masters, and when asleep they often growl, or break out into a bark, which could not be unless their mind retained the images of things before seen or perceived by some bodily sense), who can conceive rightly where these images are contained, where they are kept, or where they are formed?  If, indeed, these images were no larger than the size of our body, it might be said that the mind shapes and retains them in the bodily space which contains itself.  But while the body occupies a small material space, the mind revolves images of vast extent, of heaven and earth, with no want of room, though they come and go in crowds; so that clearly, the mind is not diffused through space:  for instead of being contained in images of the largest spaces, it rather contains them; not, however, in any material receptacle, but by a mysterious faculty or power, by which it can increase or diminish them, can contract them within narrow limits, or expand them indefinitely, can arrange or disarrange them at pleasure, can multiply them or reduce them to a few or to one.