I have been reading Julien Offray de La Mettrie's "Natural history of the soul" and "Système d'Epicure" ( thank you Charles ), and will read his "Man Machine" and "Anti Seneca" soon. I have many initial impressions, of which I will write in the future, but I'd like to bring up some points regarding La Mettrie's study of the canon, noting the following initially:
1. He was unfamiliar with Epicurus as a direct source. His familiarity was with Lucretius, which was a popular document in the intellectual life of anti-clerical intellectuals of his day.
2. Much of what he wrote were commentaries on Lucretian ideas.
3. He does not use the same words as Lucretius may have, or as Epicurus may have, in his native language to name things that we know as anticipations, canon, dogmatism, etc. He used "système" for dogmatic systems of philosophy, and referred to anticipations as they related to memory and speech.
4. This specifically bears to mind that the word "recognition" itself gives us the anticipation of a re-encounter with something that we have known previously: re-cognition. I don't know if a careful evaluation of anticipations as they relate to memory has even been done, but either way we have modern scientific insights on memory that any discussion should be checked against.
5. La Mettrie regards reason and the canonic faculties similarly to how the orthodox Epicurean does. He says of reason that it's a "mechanism which often fails". In page 93, he argues that the fact that we remember or recognize ideas with or without the consent of the will is seen as proof that they are pre-rational; ergo sub-conscious. He frequently uses the term "internal causes" here (as opposed to "external"), perhaps admitting some acknowledgement of the existence of the unconscious or subconscious mind. But that he goes to such lengths to argue that these faculties are pre-rational is very interesting to me.
The following are a few notes I've taken from La Mettrie's "Natural history of the soul" which seem to constitute, again, a commentary on Lucretius.
The first note is that he establishes anticipations as a pre-rational ("mechanic" in his words) faculty.
The cause of memory is in fact mechanic, as memory itself is. It seems to depend on that which the bodily impressions of the brain that trace ideas that follow it, are nearby, and which the soul can not discover a trace, or an idea, without remembering the others which customarily went together. - La Mettrie, speaking of the "bodily impressions of the brain in p 88-89 of "Natural history of the soul"
Ideas are "bodily impressions" in the brain. This is remarkably scientific, considering when it was written. Today we know that ideas are, concretely, electric signals shared by neurons according to established connections in the nodes between them, which are tied to habitual and instinctive behavior by the animal.
Also notice "trace ideas that follow it". This may be my awkward direct translation from the French, but the clear connotation is a pathway inside the brain. The established Epicurean conception of ideas is that they are physical and are lodged in (or happen to) the brain.
Because in order for a new movement (for instance, the beginning of a verse or a sound that hits the ears) to communicate on the field its impression to the part of the brain that is analogous to where one finds the first vestige of what one searches (that is, this other part of the brain **) where memory hides, or the trace of the following verses, and represents to the soul the follow-up to the first idea, or of the first words, it is necessary that new ideas be carried by a CONSTANT LAW to the same place to where the other ideas of the same nature as these were carried. - La Mettrie, speaking of the "constant law" by which memory functions in p 89-90 of "Natural history of the soul"
** (note: he uses the word moelle, which translates as "bone morrow", but he must be referring to brain tissue or brain lobe of some sort)
These passages in particular relate to the passage where Lucretius mentions neural pathways in the brain.
There is a reason why this was an important teaching where the ethics are concerned. Epicurus is the only teacher who ever posited a theory of moral development based on the physical structure of the brain. This has been a long-buried jewel of his genius. In his "On moral development" we find that Epicurus claimed that, in the process of moral development, one has the power to change one’s beliefs, and even to atomically change one’s mind. He speaks of how we may transform our dispositions in order to have a final developed product (a mature, happy, and healthy character)--but he SPECIFICALLY frames this in terms of changing the material / physical structure of the brain. And it's here that his moral theory rests on his physics theory.
Elsewhere La Mettrie speaks of "la penetration", of attention, of focus as a faculty of the soul. The word in Greek, epibole (translated as the act of focusing a particular faculty) is one of the words that Epicurus used in On Nature Book 18 and which seemed to be of great importance. I'm not sure what word Lucretius would have used, but if he did, then this portion of La Mattrie might be a commentary of that portion of Lucretius, which might link back and be related to the conversations from book 18 On Nature, which focuses on the importance of clarity of thought and speech.
I have many more notes on many other subjects from La Mettrie, but wanted to share these ideas here in the hopes that others make other connections I'm not making, particularly those with more familiarity with Lucretius (or the science of how memory works).
My impression is that La Mettrie was DEEPLY steeped in the study of the canon, and that his "Natural history of the soul" was an attempt to posit a non-religious theory of the self and of the mortal soul that was as scientific as you could get in the pre-Darwinian generations.