Well now, let us see where we are to locate what you might call the border between the outer and the inner man. Anything in our consciousness that we have in common with animals is rightly said to be still part of the outer man, but the body with its own kind of life attached, which quickens the body’s structure and all the sense is is equipped with in order to sense things outside. And when the images of things sensed that are fixed in the memory are looked over again in recollection, it is still something belonging to the outer man that is being done.
In this passage Augustine is continuing his discussion concerning the Trinitarian analogies in man. He distinguishes between and inner and an outer man. This passage deals with the outer man, but note what he says. He gives the animals the ability to remember, which means that they would have qualia. Qualia are those parts of human thought that cannot be reduced the neurons in the brain. In the philosophy of mind human sensations ("what it feels like") cannot be reduced to neuronal states, for how can something experienced from the first person subjective experience be reduced to the physical third person stance? It seems that my experience of redness is something very different from what a neurologist would see under an fMRI scanner. The two phenomenal have different attributes, which cannot be reduced down to one another. The significant thing about Augustine and other ancient philosophers is that the were completely fine with allowing animals to have what is called "phantasms" or images. However, Augustine reserved ratiocination or reason only to men, angels, and God. So when scientistic types point out that dogs can "remember" their masters, chimps can use "tools" etc, it should cause no problem for human uniqueness, because those functions are part of the function that produces "images" which is distinct from the faculty of reason.