Memory can be defined as “the faculty of the brain by which information is encoded, stored, and retrieved when needed” (Wikipedia). Here you see the brain is included in the definition. Is this inclusion necessary? After all, one could say that “memory is the process by which information…” and thereby leave it open as to what is doing the encoding, storing, retrieving, and so on. But even a brief inquiry into memory on the web will take you to impressive diagrams and accounts of memory as a set of neurological functions. And this seems plausible enough: Alzheimer’s disease, Parkinson’s disease, Korsakoff’s syndrome, hyperthymesia, and various forms of amnesia brought on by drug use seem to show that memory is, for all its complexity and mystery, completely neurological. Should this neurology be comprised then your mind will lose some or all of its memory. Some philosophers have taken this fact as evidence that there is no soul or immaterial substance that interfaces with, yet in principle can exist independently of, the brain: the mind is a set of material brain events and nothing beyond them.
Plotinus (204-70), however, would disagree if he suddenly came to live among us. He would, no doubt, be intrigued with the latest neurophysiology. But I suspect he would reiterate what he asserts in section 26 of Ennead IV. 3 (Problems of the Soul, I), namely, that memories “are not magnitudes (are not of corporeal nature at all), are entirely of the intellect, though exercised upon the things of sense” (see the Penguin Classics edition p. 280). Plotinus has various arguments for this claim. In this post I want to briefly consider the one he puts forth in the following passage:
“Further there is one order of which the memory must obviously belong to the Soul; it alone can remember its own movements, for example its desires and those frustrations of desire in which the coveted thing never came to the body; the body can have nothing to tell about things which never approached it, and the Soul cannot use the body as a means to the remembrance of what the body by its nature cannot know.” (280)
Plotinus is arguing there are “movements” attributable to the soul that are not attributable to the body/brain. Such movements include our desires and intentions. These movements can be contrasted with the non-intentional functions of the brain and its matter devoid of desires, longings, frustrations, etc. Can neurons have intentions? Can synapses have their goals frustrated? Can dendrites have shame over a failure to achieve the good? Plotinus would say no. Thus our memories of, say, longing for someone we love or feeling shame when we fail to act virtuously would not be locatable in the brain. The memories of such soul movements couldn’t, as Plotinus said above, come from the brain since the brain cannot have such movements and so “can have nothing to tell of about things which never approached it.” And the soul couldn’t use the brain as a tool for storage or retrieval of such memories since the brain “by its nature cannot know” them.
However, when we encounter people who appear to have lost memories of the soul’s intentional movements we begin to doubt Plotinus’ argument. If we confronted him with our doubts I think he would say the following:
“Memory, in point of fact, is impeded by the body: even as things are addition often brings forgetfulness; with thinning and clearing away, memory will often revive. The Soul is a stability; the shifting and fleeting things which body is can be a cause only of its forgetting, not of its remembering – Lethe stream may be understood in this sense – and memory is a fact of the Soul.” (281)
Our soul, insofar as it is involved with the body, necessarily drinks from the river of Lethe in Hades whose waters lead to forgetfulness (see, for example, Plato’s Myth of Er at the end of his Republic and Virgil’s Aeneid VI 703-751). The body impedes the soul’s functions and, when the soul is liberated from the body, it will be in a position to remember with far more accuracy.
But it is important to note that Plotinus doesn’t think the virtuous person, who soul’s movements and actions revolve around a longing for The Good or The One, will be remembering much from its embodied life anyway. After all, many our soul’s movements are directed towards things quite base, unspiritual, inconsequential, utilitarian, and even immoral. Only memories of our “noblest” movements will be retained:
“In this sense we may truly say that the good soul is the forgetful. It flees multiplicity; it seeks to escape the unbounded by drawing all to unity, for only thus is it free from entanglement, light-footed, self-conducted. Thus it is that even in this world the soul which has the desire of the other [The Good or The One] is passing away, amid its actual life, all that is foreign to that order. While it is in the heavenly regions it puts away more again. Little of what is gathered here is taken with it to the Intellectual Realm.” (285).
In any case, there is one of Plotinus’ interesting arguments for why the forms of memory loss with which we are familiar need not imply the non-existence of the soul or the permanent loss of memory. Of course, in order for his argument to persuasive a more rigorous account of, on the one hand, the soul’s existence and, on the other hand, the irreducibility of desires and intentions to the brain’s emergent and/or non-emergent properties is desirable. I will offer what I take to be his most powerful argument that addresses both concerns in a post coming soon.