Hmm, I'll have to read this.
Usually transhumanism is a futuristic thing -- a thought experiment about what it would take to change ourselves so much and so fast that "the human condition" doesn't really apply. Like if we stopped aging, stopped experiencing scarcity, connected our minds to the internet and thus each other, could back up, restore, copy and merge our minds, had control over programmable matter, etc. We'd be godlike compared to how we are now, nevermind hunter-gatherer ancestors. All theoretically possible in our own lifetimes, if fra-fetched
Swedenborg was a pretty wacked-out scientist and mystic who said he received scientific truths directly from angels. Ray Kurzweil, who is the main mind behind modern transhumanism, is a brilliant inventor and crackpot who takes something like 70 supplements per day to attempt to extend his life long enough to transcend biological limitations. So there's some parallel there.