Episodes 9 and 10 of season 1 of Star Trek: Picard are titled "Et In Arcadia, Ego" parts 1 and 2, respectively. One does not use a Latin title like that without it meaning something. What does the title refer to?
(My limited Latin gives the word-for-word translation "and in Arcadia, I", which is not very helpful.)
The line Et in Arcadia ego has been used in many works of art and literature. The first clear use, which established it as a set phrase/motif, is a painting by Guercino from c.1620, showing two shepherds against an idyllic pastoral background, looking at a skull and blowfly on a pedestal; this line is inscribed on the pedestal. The next well-known use is as the title a painting by Poussin from 1637–8, similarly showing pastoral characters and background, but this time contemplating a tomb.
The meaning of the phrase is very ambiguous, without context. Your literal translation And in Arcadia, I is essentially correct, but there a few points to note. Et can mean even as well as and; and Latin often omits forms of the verb to be where English would include it. So it’s usually understood as the slightly more natural (though still ambiguous) phrase Even in Arcadia, I am.
So who is this I in the line? This is understood from the context of the paintings — both of which show symbols of death, in an otherwise idyllic pastoral setting. Arcadia was a byword for such a pastoral idyll; so the I is generally understood to be death. So overall the line is traditionally understood as “Even in Arcadia [an ideal pastoral idyll], I [Death] am still present.”
There are many later uses of the line in arts and literature; they generally take this interpretation of its meaning as understood, though some also take advantage of its vagueness/ambiguity to allude to other possible interpretations as well. One notable example, which explicitly discusses its possible meanings, is Tom Stoppard’s play Arcadia.
The wikipedia article for the Poussin painting includes more details and links good sources for much of this.
It's a reference to a rather mysterious phrase used by several painters
Many articles are written about the mysterious phrase. They try to explain the origin of the words or what the phrase is specifically meant to express. Written in Latin, the words ‘Et in Arcadia Ego’ roughly translate to ‘even in Arcadia I’ or ‘And in Arcadia I go’. Because of the phrase’s seemingly unfinished thought and the scene in which it is part of, many consider the conveyance of the words to be ‘that even in Arcadia (paradise) death is inevitable’; that time did not allow for a completion.
That particular article references a book that used it as a central puzzle, which seems rather apt given the subject of the final two Picard episodes
Recognizing the letters can be re-arranged into another sentence may provide the answers. I Tego Arcana Dei translates to Begone! I conceal God’s Secrets. This sentence is found in the warning for the Maranatha puzzle. Along with Et in Arcadia Ego, it may warn a reader what action must be taken in order to be able to enter ‘Arcadia’ (state of being or place). The changing process used to reveal the hidden message (through the use of the anagram), could hint at and share this wisdom. It could be the necessity of change within. The essential action of changing conceals God’s Secrets.
The two final episodes center around
the mysterious message the Zhat Vash found, and the unraveling secrets of that message, which apparently contain some sort of way to contact a "super-race" of artificial life
which would make the name apt.
The episode title 'Et In Arcadia, Ego' (And here I am, in Arcadia) tries to elude what confines in it: That all the main characters have finally arrived to their final destination: Arcadia. Arcadia, the mythical paradise of the Eclogues, represents a final place of happiness and peace. But what Acadia has to do with Picard (the series)? For Picard (the character), whom I believe is the Ego in the iconic phrase, Acadia is the (idyllic and Melancholic) place where he hasn’t gone before. A place to fulfill his destiny. A place to die in peace.
The iconic painting of Nicholas Poussin of the Et in Arcadia Ego theme, the shepherds contemplate a tomb with the phrase written and where one of them traces the words with his fingers. The tomb, a reminder of the presence of Death, as a kind of memento mori, expresses the melancholic feelings of the shepherds.
The phrase Et in Arcadia Ego is also present for explorers, not of a far galaxy but, of the South Pacific like Claude Levi-Strauss (From Tristes Tropiques), as a theme where his melancholy -for being far from his home- distracted him for being in archetypical paradises where he shall die.
Similarly, Arcadia, emerges for the rest of the characters wrapped in complex kinds of melancholy, as an elegant solution for the upcoming denouement. i.e. Raffi's love melancholy for Picard, Narek's wrestled melancholy between his race and the synths, Soji's heroic melancholy to overturn the 'Destroyer' prophecy, Sutra's religious melancholy for survival of her 'race'. All, together, prepares us (the audience) for the final act while we ask ourselves the pertinent question: "Will Picard and his motley crew die at the end?" The only missing link (melancholy) belongs to Rios who seems to be the one with five extra guts to untie the galactic knot.
I think it's pretty obvious considering the context of the two part episode of Star Trek: Picard. The setting is a utopian society of constructed individuals where death visits and Picard, who dies, is himself constructed. Comparing this two part episode to the paintings bearing the same name we see that even in a paradise death is present and is experienced by those who go there. This leads to the question, what and where then is paradise? Remember Data desired death.
