Enneads IV.3: Psychological Questions
The Psychology of Sensation
26. If the two elements which compose the animal share in the act of sensation, the sensation is common to the soul and the body, such as the acts of piercing or weaving. Thus, in sensation, the soul plays the part of the workman, and the body that of his tool; the body undergoes the experience, and serves as messenger to the soul; the soul perceives the impression produced in the body, or by the body; or she forms a judgment about the experience she has undergone. Consequently sensation is an operation common to the soul and body.
IN ANY CASE MEMORY IS PECULIAR TO THE SOUL AND BODY.
This could not be the state of affairs with memory, by which the soul, having already through sensation perceived the impression produced in the body, preserves it, or dismisses it. It might be claimed that memory also is common to the soul and body, because its efficiency depends on the adjustments of the bodies. No doubt the body can hinder or promote the exercise of memory, without this faculty ceasing to be peculiar to the soul. How shall we try to prove that the memory of knowledge acquired by study, belongs to the compound, and not to the soul alone? If the organism be the composite of soul and body, in the sense that it is some third object begotten by their union, it will be absurd to say that it is neither soul nor body. Indeed, it could not be anything different from the soul and body, neither if the soul and body were transformed into the composite of which they are the elements, nor if they formed a mixture, so that the soul would be no more than potentially in the organism. Even in this case, it is still the soul, and the soul alone, that would remember. Thus in a mixture of honey and wine, it is the honey alone that should be credited with any sweetness that may be tasted.
THAT THE SOUL IS INCARNATE IS NOT THE CAUSE OF HER POSSESSING MEMORY.
It may again be objected that it is indeed the soul that remembers; but only because she is resident in the body, and is not pure; she must be affected in some particular manner to be able to impress the body with the forms of sense-objects; her seat must be in the body to receive these forms, and to preserve them. But to begin with, these forms could not have any extension; then they could not be either (Stoic) seal-imprints, or impressions; for in the soul there is no impulsion, nor any imprint similar to that of a seal on wax, and the operation itself by which it perceives sense-objects is a kind of thought (or intellection). Indeed, it would be impossible to speak of an impression in the act of thought. Thought has no need of the body or a corporeal quality. It is besides necessary for the soul to remember her movements, as for instance, her desires which have not been satisfied, and whose object the body has not attained; for what could the body tell us of an object which the body has not yet reached? (Speaking of thoughts), how could the soul, conjointly with the body, remember things which the body, by its very nature, could absolutely not know?