Especially in the original sense of hard-working "biological entities that can be mistaken for humans" ;-) http://en.wikipedia.org/wiki/R.U.R._(Rossum%27s_Unive

Especially in the original sense of hard-working "biological entities that can be mistaken for humans" ;-) http://en.wikipedia.org/wiki/R.U.R._(Rossum%27s_Universal_Robots) http://en.wikipedia.org/wiki/R.U.R._(Rossum%27s_Universal_Ro... Incidentally, another story by Karel Čapek - http://en.wikipedia.org/wiki/The_Absolute_at_Large http://en.wikipedia.org/wiki/The_Absolute_at_Large - features a "reactor that can annihilate matter to produce cheap and abundant energy [and] as a by-product, the absolute. The absolute is a spiritual essence".