I have not studied the Rubaiyat of Omar Khayyam so my comments can only be brief and tentative. I suspect Hiram has so maybe he will have more comment.

But if his primary parallel to Epicurus is "his attack on the theistic or conventional judgments and his praise of simple pleasures" then we would want to explore his views on physics and epistemology as those are critical to any conclusions about ethics.

Ecclesiastes in the Bible is also deeply pessimistic and shows some Epicurean influence (the Epicureans were a major school in Antioch and in the vicinity of Judea when it was written), but it can't ultimately be reconciled with E for its claim that all wisdom begins with fear of God.

My new avatar is Omar Khayyam, painting by Adelaide Hanscom (c. 1910).

The following is from Wikipedia:

"FitzGerald emphasized the religious skepticism he found in Omar Khayyam.^[10] In his preface to the Rubáiyát, he describes Omar's philosophy as Epicurean and claims that Omar was "hated and dreaded by the Sufis,..."

Quote

The extreme popularity of FitzGerald's work led to a prolonged debate on the correct interpretation of the philosophy behind the poems. FitzGerald emphasized the religious skepticism he found in Omar Khayyam.^[10] In his preface to the Rubáiyát, he describes Omar's philosophy as Epicurean and claims that Omar was "hated and dreaded by the Sufis, whose practice he ridiculed and whose faith amounts to little more than his own when stripped of the Mysticism and formal recognition of Islamism under which Omar would not hide".^[11] Richard Nelson Frye also emphasizes that Khayyam was despised by a number of prominent contemporary Sufis. These include figures such as Shams Tabrizi, Najm al-Din Daya, Al-Ghazali, and Attar, who "viewed Khayyam not as a fellow-mystic, but a free-thinking scientist".^{[7]: 663–664} The skeptic interpretation is supported by the medieval historian Al-Qifti (ca. 1172–1248), who in his The History of Learned Men reports that Omar's poems were only outwardly in the Sufi style but were written with an anti-religious agenda. He also mentions that Khayyam was indicted for impiety and went on a pilgrimage to avoid punishment.^[12]

The Rubaiyat of Omar Khayyam [excerpt]

Edward Fitzgerald

1

Wake! For the Sun, who scattered into flight

The Stars before him from the Field of Night,

Drives Night along with them from Heav'n and strikes

The Sultán's Turret with a Shaft of Light.

2

Before the phantom of False morning died,

Methought a Voice within the Tavern cried,

"When all the Temple is prepared within,

Why nods the drowsy Worshiper outside?"

3

And, as the Cock crew, those who stood before

The Tavern shouted--"Open, then, the Door!

You know how little while we have to stay,

And, once departed, may return no more."

12

A Book of Verses underneath the Bough,

A Jug of Wine, a Loaf of Bread--and Thou

Beside me singing in the Wilderness

Oh, Wilderness were Paradise enow!

13

Some for the Glories of This World; and some

Sigh for the Prophet's Paradise to come;

Ah, take the Cash, and let the Credit go,

Nor heed the rumble of a distant Drum!

14

Look to the blowing Rose about us--"Lo,

Laughing," she says, "into the world I blow,

At once the silken tassel of my Purse

Tear, and its Treasure on the Garden throw."

15

And those who husbanded the Golden Grain,

And those who flung it to the winds like Rain,

Alike to no such aureate Earth are turned

As, buried once, Men want dug up again.

19

I sometimes think that never blows so red

The Rose as where some buried Caesar bled;

That every Hyacinth the Garden wears

Dropped in her Lap from some once lovely Head.

20

And this reviving Herb whose tender Green

Fledges the River-Lip on which we lean--

Ah, lean upon it lightly! for who knows

From what once lovely Lip it springs unseen!

21

Ah, my Belovéd, fill the Cup that clears

Today of past Regrets and future Fears:

Tomorrow!--Why, Tomorrow I may be

Myself with Yesterday's Sev'n thousand Years.

22

For some we loved, the loveliest and the best

That from his Vintage rolling Time hath pressed,

Have drunk their Cup a Round or two before,

And one by one crept silently to rest.

23

And we, that now make merry in the Room

They left, and Summer dresses in new bloom,

Ourselves must we beneath the Couch of Earth

Descend--ourselves to make a Couch--for whom?

24

Ah, make the most of what we yet may spend,

Before we too into the Dust descend;

Dust into Dust, and under Dust to lie,

Sans Wine, sans Song, sans Singer, and--sans End!

71

The Moving Finger writes, and, having writ,

Moves on; nor all your Piety nor Wit

Shall lure it back to cancel half a Line,

Nor all your Tears wash out a Word of it.

72

And that inverted Bowl they call the Sky,

Whereunder crawling cooped we live and die,

Lift not your hands to It for help--for It

As impotently moves as you or I.

The Rubaiyat of Omar Khayyam [excerpt] by Edward Fitzgerald - Poems | poets.org

"A book of verses underneath the bough,
a jug of wine, a loaf of bread--and thou
beside me singing in the wilderness--

Oh, wilderness were paradise enow!"

This was a treasured statement of our philosophy when my wife and I lived a more simple life (for 15 years) in what I called our "widly garden'": growing vegetables in the kitchen garden, cutting and splitting wood for winter, planting fruit trees, gathering blackberries and wild cherries -- and my wife's homemade wine. Doesn't seem pessimistic at all to me.

But, re the Khayyam quote, I always thought Epicurus might have quipped: "Why are you in a wilderness? Are their no civilized gardens around?"

Edward Fitzgerald himself thought of Khayyam as an Epicurean (as Kalosyni noted above) rather than a Sufi, like Rumi or Hafiz; and rejected the notion that Omar’s references to wine (for example) ought to be spiritualized – in spite of attempts to do so. Omar was influenced by Lucretius, though his own poetry was more lyric than narrative-didactic (though the lessons are there).

“Khayyam is famous for having sort of Epicurean themes in his poems and meditations on mortality and death and how to live a life that is meaningful … in the face of uncertainly, really, and mortality and temporality.” Austin O’Malley (scholar of classical Persian, University of Arizona)

Omar’s references to God can be taken as (sometimes humorously) metaphorical in many ways – but definitely not as a divine persona that meddles in human affairs.

Fitzgerald’s renderings have been criticized by academics – but one is hard-pressed to find a translation equal in lyric profundity (at least in my limited experience).

At bottom, I do not find Khayyam (or Epicurus) to be pessimistic at all – and suppose that those who do, find anything outside the comfort-zone of idealism (religious or philosophical) somehow pessimistic to them.

Quote from Pacatus

But, re the Khayyam quote, I always thought Epicurus might have quipped: "Why are you in a wilderness? Are their no civilized gardens around?"

That reminds me of this:

Quote from Thus Spake Zarathustra

Here, however, did Zarathustra interrupt the foaming fool, and shut his mouth.—

Stop this at once! called out Zarathustra, long have thy speech and thy species disgusted me!

Why didst thou live so long by the swamp, that thou thyself hadst to become a frog and a toad?

Floweth there not a tainted, frothy, swamp-blood in thine own veins, when thou hast thus learned to croak and revile?

Why wentest thou not into the forest? Or why didst thou not till the ground? Is the sea not full of green islands?

After Khayyam

“And, as the Cock crew, those who stood before
The Tavern shouted—'Open then the Door.
You know how little while we have to stay,
And, once departed, may return no more.’"

– Omar Khayyam, Rubaiyat III, translated by Edward Fitzgerald (from his First Edition)

~ ~ ~

And so, to the tavern at dawn make haste,
that lively vintage tapped this morn to taste –
for yesterday’s run dry, tomorrow’s fruit
unpres't – and deign not this hour sour to waste

whilst wishing what mayest thou savor when
fortune’s flavors favor your taste buds’ ken,
from imagining and memory bruit:
fancies and dreams – once dreamt, must drowse again.

The past draught, once drunk, shall be drawn no more;
and next year’s sherry – yet to bloom with flor,
in oaken casks to ferment – still, doth wait.
This day’s quick wine thus quaff, while it may pour –

and lose not thyself in portentous lore;
nor scorn merry mirth, vain creeds to adore.

++++++++++++++

“flor” – a yeast that is used in the production of sherry (from Spanish for flower).

Written in the form of Edward Fitzgerald’s quatrains (except for the closing couplet).

Image from an illustration by Edmund Dulac from the Rubaiyat of Omar Khayyam, 1909

Pacatus ...just this morning I found a 1947 edition in the attic and this link shows what it is, and it is illustrated by Mahmoud Sayah:

Rubaiyat of Omar Khayyam by Omar, Khayyam, Edward Fitzgerald on Blind Horse Books

New York: Random House, 1947. Mahmoud Sayah. Hardcover. Translated into English Quatrains by Edward Fitzgerald, a complete reprint of the first edition and the…

www.blindhorsebooks.com

Now I will be able to read real pages...and can verify what parts are Epicurean!