Transhumanism: And lots of it, to the point where in advanced polities, anything resembling a baseline is an endangered species at best (at worst… well, there are no examples of baseline Eldrae alathis still around, right? Even the people who were born one and survived the millennia have upgraded several times by now.). Except no humans, so we call the general form transsophontism.
Scale of Scientific Sins: All of them. Absolutely all of them.
Automation: Of just about everything, as exemplified by the sheer number of cornucopia machines, AI managers and scurrying utility spiders. Unlike most of the people who got this one very badly wrong, however, in this Galaxy, almost no-one is stupid or malicious enough to make the automation sophont or volitional.
GE and Transhumanism: Transsophontism Is Compulsory; those who fall behind, get left behind. Or so say all we – carefully engineered – impossibly beautiful genius-level nanocyborg demigods. (Needless to say, Cybernetics Do Not Eat Your Soul.)
Immortality: Possibly cheating, since the basic immortality of the eldrae and galari is innate – well, now it is, anyway – rather than engineered. Probably played straight with their idealistic crusade to bring the benefits of Avoiding That Stupid Habit You Have Of Dying to the rest of the Galaxy, though.
Creating Life: Digital sapience, neogens (creatures genetically engineered from scratch, rather than modified from an original), and heck, even arguably uplifts, too.
Cheating Death: The routine use of vector stacks and reinstantiation is exactly this. Previously, cryostasis, and the entire vaults full of generations of frozen people awaiting reinstantiation such that death would bloody well be not proud. And no, people don’t Come Back Wrong; they come back pretty much exactly the same way they left.
Usurping God: This one is a little debatable, inasmuch as the Eldraeverse does not include supernatural deities in the first place. On the other hand, if building your own complete pantheon of machine gods out of a seed AI and your own collective consciousness doesn’t count towards this, what the heck does?
…for those also interested in the bits of eldraeic theology I’ve published now and again on this site.
Slate Star Codex: The Goddess of Everything Else
Emergency Transformation: This is another thing that tends to happen a lot – not so much for the Imperials themselves, who are used to changing bodies, and for that matter substrates – “at home I’m a humanoid; at work I’m a squidbot” – like other people change suits, but as you might expect from people who do that, they do keep the appropriate scan-and-compile machinery around when a friend of theirs seems to be about to get dead, because, well, the standard medical treatment for that is to have your brain scanned, your mind-state compiled, and your selfness reinstantiated in another body equipped with proper universal noetic architecture.
This works about as well as you might imagine when you consider the number of people in the universe who remain fundamentally uncomfortable with the algorithmic view of mind (“souls are software objects”) even if they aren’t actual biochauvinists/carbon chauvinists, or who are concerned that some immaterial essence isn’t going along with the transfer, or some such. And, of course, the Imperials are about as equipped to deal with this one as they are the Cloning Blues (“What sort of fucked-up society spreads memes like this around anyway?”) in the sense of not really having much empathy for any position quite so weird.
And there’s only so far slapping people upside the head with science will go. Or explaining yet again that if you think you’re you, and remember being you, and act like you, then you are you to within all relevant standards of you-ness, ‘kay? And, hey, you got immortality, light-speed-plus travel and optional superpowers out of this deal, so could you maybe stop whining for a minute and learn to enjoy not being dead already?
Yeah. Like that.
No Transhumanism Allowed: Averted (or rather inverted into Transsophontism Is Mandatory). Hard. (As in, anyone who doesn’t qualify as some sort of transsophont is living in Hicksville or on the moral equivalent of a nature preserve.) Also beaten, mocked, eaten by nanobots, shot at with antideuterium pellets and tossed down a singularity well. A lot.
Perhaps, if it turns out transhumanism (or, rather, its polyspecific analog, transsophontism) is the development path all species end up taking once they have the ability to do so, the problem is that once they’ve spent much time and effort on engineering themselves into ever-more brilliant and beautiful forms, they rest of the universe becomes simply too unbearably stupid and ugly to interact with…
And so they don’t.
And they become pretty damn good at hiding from SETI searches, too, because the last thing they want is any of these ugly morons turning up on their doorstep.
Simply revolting, sweetie.
All I can say is that I’ve never met a sad centenarian.