Prolepses are one of the theories of Epicurus that have very little remaining in his extant writings. Recently I gave Plato’s Phaedo a quick read, and one thing that struck me was this passage. The context of this argument is in direct contrast to Epicurus’ universe of atoms and void, and similarly to his theory that the “soul” begins and ends at birth. Which would lead one to the conclusion that Epicurus was probably looking closely at this from time to time as he formulated his counter argument. This particular portion appears to relate to the prolepses, and it is part of a “proof” that we have an eternal soul:
Then before we began to see or hear or perceive in any way, we must have had a knowledge of absolute equality, or we could not have referred to that standard the equals which are derived from the senses?— for to that they all aspire, and of that they fall short.
And if we acquired this knowledge before we were born, and were born having the use of it, then we also knew before we were born and at the instant of birth not only the equal or the greater or the less, but all other ideas; for we are not speaking only of equality, but of beauty, goodness, justice, holiness, and of all which we stamp with the name of essence in the dialectical process, both when we ask and when we answer questions. Of all this we may certainly affirm that we acquired the knowledge before birth?
But if, after having acquired, we have not forgotten what in each case we acquired, then we must always have come into life having knowledge, and shall always continue to know as long as life lasts— for knowing is the acquiring and retaining knowledge and not forgetting. Is not forgetting, Simmias, just the losing of knowledge?
But if the knowledge which we acquired before birth was lost by us at birth, and if afterwards by the use of the senses we recovered what we previously knew, will not the process which we call learning be a recovering of the knowledge which is natural to us, and may not this be rightly termed recollection?
So much is clear— that when we perceive something, either by the help of sight, or hearing, or some other sense, from that perception we are able to obtain a notion of some other thing like or unlike which is associated with it but has been forgotten. Whence, as I was saying, one of two alternatives follows:— either we had this knowledge at birth, and continued to know through life; or, after birth, those who are said to learn only remember, and learning is simply recollection.
Then, Simmias, our souls must also have existed without bodies before they were in the form of man, and must have had intelligence.
Unless indeed you suppose, Socrates, that these notions are given us at the very moment of birth; for this is the only time which remains.
Yes, my friend, but if so, when do we lose them? for they are not in us when we are born— that is admitted. Do we lose them at the moment of receiving them, or if not at what other time?
No, Socrates, I perceive that I was unconsciously talking nonsense.
Then may we not say, Simmias, that if, as we are always repeating, there is an absolute beauty, and goodness, and an absolute essence of all things; and if to this, which is now discovered to have existed in our former state, we refer all our sensations, and with this compare them, finding these ideas to be pre-existent and our inborn possession— then our souls must have had a prior existence, but if not, there would be no force in the argument? There is the same proof that these ideas must have existed before we were born, as that our souls existed before we were born; and if not the ideas, then not the souls.
Edited from Plato: The Complete Works (31 Books) (p. 767-770). Titan Read Classics. Kindle Edition.
Does this passage add any clarity to how we can understand the prolepses? If we examine the opposite of everything Plato describes here, can we replicate a part of Epicurus’ process of conceiving the prolepses?
I see in here a potential source for Diogenes Laertius’ “cow explanation” of prolepses as things learned from repeated exposure, which would seem to reduce its credibility. Also the eidola would relate to this, and DeWitt’s idea of a prolepsis as an embryonic notion or sketch of an idea. Then of course there’s the fact that we have modern neuroscience to consider once we reach some sort of understanding of Epicurus’ conception. I haven’t had a chance to digest the full implications yet!
but to me, infinitely small is different from infinite in extent. One Epicurean argument is against infinite divisibility of atoms, but I'm not even sure if this is addressing that argument. Another Epicurean argument is that the universe is infinite in extent, but it doesn't seem like he's addressing that argument. He mentions infinities of different sizes, but again I think that applies to number but not extent (?).