Negative Bliss- the absence of any sentient state which can be described as less than perfectly blissful.
The more I think about it, the more I find the whole notion of positively maintained bliss problematic. All my experience tells me that part of the essence of happiness is tied into a sort of relative comparison matrix; the crest of a wave, whose body is the whole of a person's spectrum of temperament. I'm not aware of any studies at present, but I suspect that extreme peaks of joy tend to flatten out pretty quickly. I'm not even sure if happiness removed from its unabridged frame of reference makes any sense at all.
Of course, a challenge can be raised regarding the subjective assessments I'm making in order to come to this conclusion. But regarding happiness, what other yardstick can possibly apply? Obviously, I can become more fully aware of the context of circumstances out of which my happiness emerges; comparing the actual state of affairs to my personal moral framework, for instance, to see if my feelings are actually warranted vis-a-vis consistency. But in the end, I'm still stuck with how I feel about things...happy, sad, or indifferent.
That said, I'm far from convinced that one can be intrinsically happy, any more than one can be intrinsically tall. It's all about context, and the context of existence is in constant flux. Even in the imaginary brains-in-vats scenario, surely its proponents envision the process of thought continuing, and probably at a faster and greater rate than hitherto known. And, as anybody knows, thinking is rarely a straight-line affair. Thoughts compete; they bump up against each other. They challenge one another. The very process of thought itself requires comparison i.e. relativity, and I see no reason to think that mood wouldn't follow this very same course.
Furthermore, the positive bliss enthusiasts make a HUGE speculative leap in their presumptions about just how high these 'peaks of bliss' can rise. Who's to say that future levels of happiness will be that much higher than they are now, on a good day? I suspect that we can tweak things here and there, but unless we're talking about refashioning humanity from the ground up, along with all the experiential stuff that makes us human, then a lot of this talk seems like an exercise in extreme overestimation to me. On top of which, if our imagined destiny IS that far divorced from our present human experience, who KNOWS what new, impossible to presently imagine problems might come along to give our freshly starched Shangrila a nice kick in the pants?
All things considered, I think much of this transhumanist stuff is talking-out-of-the-ass talk. It's been pointed out before, for instance, that our artistic visions of Hell are replete with details, including levels and degrees of suffering. But denizens of Heaven (when Heaven is depicted at all) seem to spend most of their time walking around in suits with thin ties, sort of staring into space like opium addicts. This is because we really can't get our minds around the idea of unadulterated, intrinsic happiness. That's why there's a Hell in the first place, so that those living in Heaven will realize that they're happy... by comparison.
Lastly, there's absolutely no guarantee that, once having reached whatever manifested 'promised land' one might care to imagine, eventually someone, or something, won't move in and muck up the works. To absolutely guarantee a perfectly maintained state of bliss for everyone, for all time, somebody's gonna have to have a set of reins on the whole frickin' universe. All I can say to that is...good luck with that!
Meanwhile, the ugly stepsister, Negative Bliss, stands waiting...
What do dogooders do? Why, they minimize the bad, to the best of their ability. They alleviate hunger. They mend wounds. They bury the dead. Most of what we recognize as 'good', is actually the absence of 'bad'. The more bad we manage to erase, the more good naturally comes into its own. And this is where antinatalism rides in on a white horse; for with every person never conceived, one full lifetime of potential harm is erased from the ledger. No, more than erased; it's never recorded in the first place! Thus one human unit of the negation of all suffering is fully actualized...negative bliss! And unlike the other kind, negative bliss is definitionally guaranteed to last forever, as applied to the potential person who never came to be. Potential people are invulnerable to harm, plain and simple. And why not? It's where we're all headed in short time, anyway. Why create vessels of suffering who will, in very short order, pass away into the negative bliss of non-existence, when the potential to never exist is there right now? Why bring this unfortunate manifestation into an existence of suffering, when the end is where we started from? It's like catching a crappy, smelly bus from your home, in order to get home...why not just stay in the house? Kick back, crack open a brew, and watch the game... relax!
In a negative bliss sort of way, of course.