The idea of the technological singularity has famously been called the "rapture of the nerds".
I have observed various unsettling parallels between the religious/spiritual ideas and symbols of people from times before the singularity was supposed, and ideas of the singularity. The most obvious explanations I can think of are these. First, perhaps the supernatural exists, and past thinkers had conveyed to them something of the essence of future events, albeit in a veiled/metaphorical form. Second (and since I do not currently believe in the supernatural, this is the explanation I prefer), perhaps archetypes (whether fundamental to the construction of the human mind, or merely conveyed obscurely by culture) have more influence on our thought than we can easily see, and that the thining of both these older religious thinkers and also the modern technological singularity futurists are being structured by these archetypes, causing their conclusions to cohere more closely than would be the case if the thought of each were totally unconstrained.
Here I will note down examples of older non-technological thinkers who say things that can be interpreted as a metaphor for something scifi-ish:
- I have not read it myself, but everyone talks about Teilhard de Chardin.
- Christian fiction speaks of the devil as someone to whom you can sell your soul, which doesn't appear to do any immediate damage to you, but which consigns you to misfortune for eternity. This can be interpreted as selling an upload of your mind; this won't injure you, but your uploaded self might persist for an indefinite amount of time, experiencing whatever its possesor desires it to experience, and possibly being interrogated or even directly read or directly altered.
- Swendenborg's description of the people from Mercury sounds much like a knowledge-seeking, spacefaring posthuman society that forms limited groupminds (similar to a spacefaring version of what Vinge described as the state of human society around the character Tunc's time in the scifi book "Marooned in Realtime"):
- Islamic Jinn (genies) sound something like electronic beings (or other "energy-based" beings, interpreted in the scifi way; literally, of course, humans are already "energy-based"): "In Islamic theology jinn are said to be creatures with free will, made from 'smokeless fire' by Allah in the same way humans were made of earth." -- http://en.wikipedia.org/wiki/Genie
- Islamic eschatology speaks of an antichrist who can be interpreted as someone who is a materialist: "Everyone will be able to read the word ‘Kafir’ [disbeliever], inscribed in bold letters, within his two eyes." cyborg: "His right eye will be punctured, and his left eye would be raised to his forehead and will be sparkling like a star." with a mechanical vehicle: "He will be riding on a huge white coloured 'donkey' who will cover a mile in a single stride." and who threatens people with some sort of futuristic torture (perhaps upload-based): "He will have a hell fire and a paradise by his side and people that will refuse to follow him, will be forced to enter the hell-fire, that accompanies him. However, this will merely be an illusion and this will, in reality be cool and safe for this person.". All quotes in this paragraph from http://en.wikipedia.org/wiki/Dajjal.
- Christian eschatology (Book of Revelations) speaks of a "mark of commerce": "He also forced everyone, small and great, rich and poor, free and slave, to receive a mark on his right hand or on his forehead, so that no one could buy or sell unless he had the mark, which is the name of the beast or the number of his name." This could be realized with an implantable microchip (or similar) which identifies and authenticates the bearer.