"Uploading a mind will make it much easier to enhance its intelligence, by running it faster, adding additional computational resources, or streamlining its architecture. One could imagine that enhancing an upload beyond a certain point will result in a positive feedback loop, where the enhanced upload is able to figure out ways of making itself even smarter; and the smarter successor version is in turn even better at designing an improved version of itself, and so on. If this runaway process is sudden, it could result in one upload reaching superhuman levels of intelligence while everybody else remains at a roughly human level."
- Nick Bostrom, Existential Risks, Journal of Evolution and Technology, Vol. 9, March 2002.