Thanks Burning lights. We will compile a table and include in one or both lists:
I'd imagine that for many if not most modern American Christians, their beliefs about the Christian god are in fact one of their greatest sources of comfort and not distress
That is no doubt thought to be true in many cases. What to do in response to it is a separate question, and no doubt varies by personal context and goals. It's definitely something that many people believe in their own lives to be the case, and so something to consider in the mix.
It seems most productive to me to find a way to attract people who would tend to be interested in the first place. I don't really think that a devout Christian or idealist will ever find EP attractive unless they get disillusioned with their current situation and are looking for alternatives. So I see the obstacles to revival in large part as obstacles to finding like minded folks.
Good suggestions so far. In addition, before we go too far down the "current obstacles" road, it would probably help to be sure to include comments on factors in the ancient world that led to decline. Many of the "obstacles" we see today were present during the rise of Epicurean philosophy, and yet rise it did. What caused the rise to slow and reverse? Was Christianity really so persuasive intellectually? 
What other factors played a part? Especially since a decline seems to have set in even before Christianity rose?
Or did it? When did the decline really begin? Was Lucretius really the last powerful *explicit* Epicurean writer? We can say Diogenes of Oinoanda came later, but to some extent he seems to be a special case.
So please everyone keep going, and consider both time periods.
Burning lights you are of course also raising the background question of what it is we are talking about in terms of decline and revival - whether the focus is on ethics primarily or the full picture.
It's definitely legitimate to talk about eclecticism especially as an entry point. However for purposes of the discussion let's presume that what we are talking about both in the past and in the intervening years would be the status of claiming "I am an Epicurean" and meaning by that that the person is making the point that he or she endorses the full philosophy of Epicurus - -- not necessarily every precise point of "science" at the atomic level, but including every major point of canonics, ethics, and the nature of the universe professed by Epicurus. Which is what you would expect an organized "school" would likely do.
Now of course that kind of standard applies more clearly to the intervening centuries than to 2023, but I think the basic point remains valid, and revolves around seeing Epicurus as the core organizing figure of a philosophy that he would clearly recognize as his own if he were alive at any point in the last 2000 years or even today.
For purposes of this exercise we aren't saying necessarily that we ourselves would take that path tomorrow. The main point here is analyzing the big picture in the abstract, sort of along the lines of Gibbon diagnosing the fall of Rome, for us to discuss in the podcast.
Any further ambitions beyond that should be reserved for another day. 
. Putting a period to this series of episodes of the podcast is the immediate objective. All comments so far have been great so we will hope for many more over the next week.
As a shorter way of saying what I stated in that last post, below is a table I am setting up in the thread for the next podcast episode. For the table I am tweaking the title of Kalosyni's first post (which is already a little unwieldy) to try to bring a little more focus to what we want to talk about on the podcast. Even this tweaking still leaves a lot of ambiguity, but hopefully it helps.
For example, I really want to make the title "as a movement where people PUBLICLY identify their primary worldview as Epicurean," and that should be implicit in the discussion. However that brings in questions of "affiliation with a group," which is beyond the scope of this discussion, so let's try to separate the issue of an "official" identification from that of what a person in their own minds is doing.
So for example, let's consider the main issue not as counting numbers of avowed "public" Epicureans, but evaluating what it took from 50 BC to say 1700 AD for people in their own personal lives to consider their own worldviews to be primarily aligned with what Epicurus taught. No doubt many of those same factors extend to the present, but talking about the present implies more than we want to take on at the moment. What we'll address in the podcast is "factors" - not proposed solutions. "Solutions" is too big a topic to tackle in an hour long final podcast.
So the titles of the lists for the podcast will be:
Let's keep the majority of the conversation here, but for purposes of the podcast as we near the date of recording we'll update the final list here: RE: Episode 189 - "Epicurus And His Philosophy" Part 41 - Chapter 15 - Extension, Submergence, & Revival 04 (Not Yet Recorded)
For many if not most modern American Christians, their beliefs about the Christian god are in fact one of their greatest sources of comfort and not distress (burninglights)
Ditto for an afterlife: there are people, not limited to Christians, who take great comfort in their belief in an afterlife.
Right. Other than for Lucretius' poetic version, we don't know when or if Epicurus' "On Nature" or even his letters or the sayings were translated into Latin in the ancient world, if at all. Greek may have been the language of the intellectuals but the common people would have eventually needed Latin, so "getting the texts into easily accessible form" has to always be a priority. Were they successful in doing so in the ancient world other than in the negative form of being included in Cicero's attacks?
So I'll add to the list: "Possibility that the texts were not translated into Latin or local languages in sufficient numbers to penetrate deeply enough into common culture."
So I'll add to the list: "Possibility that the texts were not translated into Latin or local languages in sufficient numbers to penetrate deeply enough into common culture."
You also have to take into account literacy rates back then.
For many if not most modern American Christians, their beliefs about the Christian god are in fact one of their greatest sources of comfort and not distress (burninglights)
Ditto for an afterlife: there are people, not limited to Christians, who take great comfort in their belief in an afterlife.
It occurs to me that the comforting aspects of Epicureanism could have gotten lost as time went on.
Is it only in Lucretius that we see the metaphor of honey on the rim of wormwood? And I would say that this is a subjective evaluation anyway -- and it puts a dark twist on things that isn't needed.
Perhaps Epicurus originally had a much more comforting message in his emphasis in friendship - PD29 and in feeling secure - PD 39. But as time went on this somehow got overshadowed, and at the time of Horace there is the emphasis on pleasure itself ("Epicuri de grege porcus") more than the requisites of a pleasurable life. Subtle things like these two issues could lead to Epicureanism becoming less useful and less helpful. It could be that the "big picture" understanding was lost, and that also contributed to the decline.
A far as comforting or not, the refutation of the fear of the gods and of death is consistently cited as primary in the philosophy. Those are the first two "doctrines" in Principal Doctrines, Diogenes of Oenoanda's inscription, the "Vatican Sayings" (ie, The Voice of Epicurus), the first two lines of the Tetrapharmakos, etc.
Those two doctrines are not necessarily comforting to those who hold tightly to being looked after by a god and loving eternally with said god.
Great comments Burninglight and thanks for that suggestion as to materialism.
And I had never heard of that Horace quote but the litany of examples reminds me immediately of the list of misbegotten love interests in Lucretius Book IV. I wonder if there's any pattern or parallel there worth considering as to form of presentation, or if it is totally coincidental?
For this men usually do, blinded by passion, and attribute to the beloved those advantages which are not really theirs. We therefore see women in ways manifold deformed and ugly to be objects of endearment and held in the highest admiration. And one lover jeers at others and advises them to propitiate Venus, since they are troubled by a disgraceful passion, and often, poor wretch, gives no thought to his own ills greatest of all. The black is a brune, the filthy and rank has not the love of order; the cat-eyed is a miniature Pallas, the stringy and wizened a gazelle; the dumpy and dwarfish is one of the graces, from top to toe all grace; the big and overgrown is awe-inspiring and full of dignity. She is tongue-tied, cannot speak, then she has a lisp; the dumb is bashful; then the fire-spit, the teasing, the gossiping turns to a shining lamp. One becomes a slim darling then when she cannot live from want of flesh; and she is only spare, who is half-dead with cough. Then the fat and big-breasted is a Ceres’ self big-breasted from Iacchus; the pug-nosed is a she Silenus and a satyress; the thick-lipped a very kiss. It were tedious to attempt to report other things of the kind.
I actually think Horace has some lovely descriptions of friendship and wider Epicurean concerns in his works, so I'd argue against him being to blame. Here he is on friendship, from Satire 1.3
Horace is devilishly difficult to pin down, unfortunately. But first, a chronology;
[Assassination of Caesar, 44 BC]
[Battle of Philippi, 42 BC]
[Lepidus Exiled, 36 BC]
Satires 1 (c. 35–34 BC)
[Battle of Actium, 31 BC]
Satires 2 (c. 30 BC)
Epodes (30 BC)
[Reign of Augustus Begins, 27 BC, followed by military adventuring. Returns to Rome 24 BC]
Odes 1–3 (c. 23 BC)
Epistles 1 (c. 21 BC)
Carmen Saeculare (17 BC)
Epistles 2 (c. 11 BC)
Odes 4 (c. 11 BC)
Ars Poetica (c. 10–8 BC)
Now then. Between Philippi and Actium Horace wrote his first book of Satires, with distinct Epicurean themes and borrowed Lucretian diction; according to Wikipedia, "Lucretian stock phrases such as nunc ad rem redeo ("now I return to the matter at hand") give Horace's philosophical "conversations" (Sermones) a subtly Lucretian flavor." In the fifth Satire of the first book, he paraphrases the Epicureans on the nature of the gods;
Hence we came to Rubi, fatigued: because we made a long journey, and it was rendered still more troublesome by the rains. Next day the weather was better, the road worse, even to the very walls of Barium that abounds in fish. In the next place Egnatia, which [seems to have] been built on troubled waters, gave us occasion for jests and laughter; for they wanted to persuade us, that at this sacred portal the incense melted without fire. The Jew Apella may believe this, not I. For I have learned, that the gods dwell in a state of tranquillity; nor, if nature effect any wonder, that the anxious gods send it from the high canopy of the heavens.
In 30 BC come the Epodes, and the ninth in the set has Horace (a former officer in the Republican Army) toasting assiduously the victory of Octavian at Actium, and likewise condemning Cleopatra as an Egyptian seductress when she was, in fact, a Macedonian heiress and a student of several languages who conversed with her Latin conquerors in Greek.
When, O happy Maecenas, shall I, overjoyed at Caesar's being victorious, drink with you under the stately dome (for so it pleases Jove) the Caecuban reserved for festal entertainments, while the lyre plays a tune, accompanied with flutes, that in the Doric, these in the Phrygian measure? As lately, when the Neptunian admiral, driven from the sea, and his navy burned, fled, after having menaced those chains to Rome, which, like a friend, he had taken off from perfidious slaves. The Roman soldiers (alas! ye, our posterity, will deny the fact), enslaved to a woman, carry palisadoes and arms, and can be subservient to haggard eunuchs; and among the military standards, oh shame! the sun beholds an [Egyptian] canopy.
Following Augustus' return to Rome in 24 BC as Imperator, Horace published his first book of Odes and begins in the same vein;
[...] If thou, the winged son of gentle Maia, by changing thy figure, personate a youth upon earth, submitting to be called the avenger of Caesar; late mayest thou return to the skies, and long mayest thou joyously be present to the Roman people; nor may an untimely blast transport thee from us, offended at our crimes. Here mayest thou rather delight in magnificent triumphs, and to be called father and prince: nor suffer the Parthians with impunity to make incursions, you, O Caesar, being our general.
And in the 34th Ode in the same book, there is a direct repudiation of Lucretius. In his sixth book, Lucretius strove by several arguments to make the case that lightning did not come from the gods. One of the arguments he made was that if lightning came from Jupiter, then Jupiter had no need of cloud to let fly the bolt--so why is it that lightning is not seen on a cloudless day?
"But if Jupiter and other gods shake
bright heavenly spaces with dreadful noise
and hurl down fire to any place at all,
according to what each of them desires,
why do they not see to it that those men
who in their recklessness have committed
abominable acts are struck and stink
of lightning fires from hearts pierced by the bolt,
a bitter precedent for mortal men?
Why instead is the man who is aware
he himself has committed no wrong act
in his innocence entangled and wrapped
in flames, snatched up in fiery hurricanes
suddenly sent down from heaven? Besides,
why do they target isolated places
and work so hard for nothing? Or are they
exercising limbs, toning their muscles?
Why do they allow their father’s weapon
to be blunted on the earth? Why does he
let that happen and not save the lightning
for his enemies? Why does Jupiter
never hurl down his lightning bolt on earth
or let his thunder peal when skies are clear
in all directions? Or as soon as clouds
appear, does he himself go down to them,
so that from there he may guide the impact
his weapons make from close at hand? And why
does he send them into the sea? What charges
does he bring against that liquid mass of waves,
those fields of water? And if he wants us
to beware the stroke of his thunderbolt,
why is he reluctant to arrange things
so we can see it as he hurls it down?
But if he wishes to overwhelm us
with his lightning when we are unaware,
why does he thunder from that area,
so we can guard against it? Why does he
first stir up darkness, noises, and rumbling?
And how can you believe he discharges
lightning to many places all at once?
Would you dare to say it never happens
that many strikes occur at the same time?
But that has happened very frequently
and must take place—just as rain and showers
fall in many spots, so numerous thunderbolts
are formed at the same time. And finally,
why does he destroy the sacred temples
of the gods and his own splendid dwellings
with hostile lightning and smash to pieces
well fashioned idols of the gods, robbing
his own images of their dignity
with a violent wound? Why for the most part
does he aim at high places, for we see
most traces of his fire on mountain tops?"
I cannot claim to know why or what it means, but Horace latches on to this argument in order to make the reverse case; lightning has struck on a cloudless day, therefore Lucretius was wrong about the gods. To tell the truth, it's always difficult to know with Horace whether he's being completely serious. But the final quote that I will share here is often repeated, and this Ode seldom taken into consideration;
A remiss and irregular worshiper of the gods, while I professed the errors of a senseless philosophy, I am now obliged to set sail back again, and to renew the course that I had deserted. For Jupiter, who usually cleaves the clouds with his gleaming lightning, lately drove his thundering horses and rapid chariot through the clear serene; which the sluggish earth, and wandering rivers; at which Styx, and the horrid seat of detested Taenarus, and the utmost boundary of Atlas were shaken. The Deity is able to make exchange between the highest and the lowest, and diminishes the exalted, bringing to light the obscure; rapacious fortune, with a shrill whizzing, has borne off the plume from one head, and delights in having placed it on another.
What's strange is that two years later he publishes his first book of epistles, and with it the most famous Epicurean quote in his whole body of work.
Albius, thou candid critic of my discourses, what shall I say you are now doing in the country about Pedum? Writing what may excel the works of Cassius Parmensis; or sauntering silently among the healthful groves, concerning yourself about every thing worthy a wise and good man? You were not a body without a mind. The gods have given you a beautiful form, the gods [have given] you wealth, and the faculty of enjoying it.
What greater blessing could a nurse solicit for her beloved child, than that he might be wise, and able to express his sentiments; and that respect, reputation, health might happen to him in abundance, and decent living, with a never-failing purse?
In the midst of hope and care, in the midst of fears and disquietudes, think every day that shines upon you is the last. [Thus] the hour, which shall not be expected, will come upon you an agreeable addition.
When you have a mind to laugh, you shall see me fat and sleek with good keeping, a hog of Epicurus' herd.
It is noteworthy that this reference to Epicurus comes immediately on the heels of a short passage on death. Perhaps that was the connection with Epicureanism that mattered to him most.
Small things like the loss of manuscripts could have had an effect:
Though less famous than the purported burning of the Library of Alexandria, the great fire that tore through central Rome in 192 CE resulted in a similarly profound loss for ancient Greek and Roman scholarship. The true cost of this fire became clear to historians in 2005, when a text believed lost for centuries was unexpectedly rediscovered in a Greek monastery. Titled “On Consolation from Grief” and written in the aftermath of the blaze by Galen—court physician to several Roman emperors—the work does more than chronicle an unfortunate accident.
Another possible cause of the decline: neoplatonism
... the Roman religious revolution preceded Constantine the Great’s rule, and it was not primarily about Christianity.
Historians’ estimates for the number of Christians during Constantine’s reign vary, but they tend to hover between less than 5% to 10% of the population at the most. The Christians up to this point had been a heavily persecuted group, particularly under Emperor Diocletian. If Constantine’s support of the Christian religion was a pragmatic choice, it cannot have been because Christianity was suddenly the largest religion.
It is popularly believed that Christianity spread primarily amongst the poor, the enslaved, and women first before it caught on with the Roman aristocracy. Jesus’ belief that the downtrodden should be cared for was part of its appeal to various groups of disenfranchised people.
On the other hand, while the Christian religion was probably not yet massive, mystery cults and foreign religions were replacing traditional pantheism with lightning speed.
This was due in part to a philosophical movement called Neoplatonism. From the 3rd century onwards, this school of philosophy basically went unchallenged and supplanted all others. Traditional philosophical education for the aristocratic population of the late Roman Empire would often entail studying at the feet of one of the many Neoplatonist philosophers.
This school is very important for understanding late Roman culture and religion. Its system of philosophy taught that, even if there are other Godlike beings, there is primarily one single all-encompassing ineffable Godhead, which is connected to the divine intellect. They were also concerned with the status of the soul of man in a divine hierarchy. These ideas were, in effect, a religious interpretation of Plato.
Its system of philosophy taught that, even if there are other Godlike beings, there is primarily one single all-encompassing ineffable Godhead, which is connected to the divine intellect. They were also concerned with the status of the soul of man in a divine hierarchy.
And that's one reason why Christian authors and evangelists were so willing to incorporate these ideas into their theology. The whole "the Word was God" stuff of the Gospel of John is unadulterated Greek philosophy. On Neoplatonism, WP has a nice article:
Neoplatonism and Christianity - Wikipedia
Edit: it appears there are some similarities in John 1:1 with the Wisdom literature of Hebrew theology, but there is also a huge strain of ancient Greek philosophy of the time. Stoicism could also be incorporated into Christian theology, so the Christian amoeba simply subsumed the Greek philosophy it wanted to and left the rest in its wake.
So, there's two topics here - as has been noted - there is the decline of the impact of the Epicurean school before the "triumph" 
of Christianity and after. However, it should be remembered that that fresco of the "triumph" of ("St.") Augustine was painted 1350-1400 so even that late, Epicurus was still a figure who held enough significance and allegorical meaning that he needed to be portrayed as someone who needed to be trod underfoot and subdued.
