In ‘Meno,’ Plato’s character (and old teacher) Socrates is challenged by Meno with what has become known as the sophistic paradox, or the paradox of knowledge: ‘And how are you going to search for [the nature of virtue] when you don’t know at all what it is, Socrates? Which of all the things you don’t know will you set up as target for your search? And even if you actually come across it, how will you know that it is that thing which you don’t know?’
In other words, if you don’t know any of the attributes, properties, and/or other descriptive markers of any kind that help signify what something is (physical or otherwise), you won’t recognize it, even if you actually come across it. And, as consequence, if the converse is true, and you do know the attributes, properties and/or other descriptive markers of this thing, then you shouldn’t need to seek it out at all. The result of this line of thinking is that, in either instance, there is no point trying to gain that ‘something’; in the case of Plato’s aforementioned work, there is no point in seeking knowledge.
Socrates’ response is to develop his theory of anamnesis. He suggests that the soul is immortal, and repeatedly incarnated; knowledge is actually in the soul from eternity, but each time the soul is incarnated its knowledge is forgotten in the shock of birth. What one perceives to be learning, then, is actually the recovery of what one has forgotten. (Once it has been brought back it is true belief, to be turned into genuine knowledge by understanding.) And thus Socrates (and Plato) sees himself, not as a teacher, but as a midwife, aiding with the birth of knowledge that was already there in the student.
The theory is illustrated by Socrates asking a slave boy questions about geometry. At first the boy gives the wrong answer; when this is pointed out to him, he is puzzled, but by asking questions Socrates is able to help him to reach the true answer. This is intended to show that, as the boy wasn’t told the answer, he could only have reached the truth by recollecting what he had already known but forgotten.
In ‘Phaedo,’ Plato develops his theory of anamnesis, in part by combining it with his theory of Forms (which holds immaterial forms as more ‘real’ than the physical world). First, he elaborates how anamnesis can be achieved: whereas in ‘Meno’ nothing more than Socrates’ method of questioning is offered, in ‘Phaedo’ Plato presents a way of living that would enable one to overcome the misleading nature of the body through katharsis (Greek: ‘cleansing’ (from guilt or defilement), ‘purification’). The body and its senses are the source of error; knowledge can only be regained through the use of our reason, contemplating things with the soul (noesis).
Secondly, he makes clear that genuine knowledge, as opposed to mere true belief (doxa), is distinguished by its content. One can only know eternal truths, for they are the only truths that can have been in the soul from eternity. Though it can be very useful to have a true belief about, say, the best way to get from London to Oxford, such a belief does not qualify as knowledge; how could the human soul know such factually contingent propositions for all eternity?
For the later interpreters of Plato, anamnesis was less an epistemic assertion than an ontological one. Plotinus himself did not posit recollection in the strict sense of the term, because all knowledge of universally important ideas (logos) came from a source outside of time (Dyad or the divine nous), and was accessible, by means of contemplation, to the soul as part of noesis. They were more objects of experience, of inner knowledge or insight, than of recollection. Despite this, in Neoplatonism, the theory of anamnesis became part of the mythology of the descent of the soul.
Porphyry’s short work ‘De Antro Nympharum’ (ostensibly a commentary on the brief passage in ‘Odyssey’) elucidated this notion, as did Macrobius’s much longer ‘Commentary on the Dream of Scipio.’ The idea of psychic memory was used by Neoplatonists to demonstrate the celestial and immaterial origins of the soul, and to explain how memories of the world-soul could be recalled by everyday human beings.
As such, psychic recollection was intrinsically connected to the Platonic conception of the soul itself. Since the contents of individual ‘material’ or physical memories were trivial, only the universal recollection of Forms, or divine objects, drew one closer to the immortal source of being. Anamnesis is the closest that human minds can come to experiencing the freedom of the soul prior to its being encumbered by matter. The process of incarnation is described in Neoplatonism as a shock that causes the soul to forget its experiences (and often its divine origins as well).