search for better power sources. What is notable in these three rules is that these are basically rules for "wild" life, so in essence what Tilden stated is that what he wanted was "proctoring a silicon species into sentience, but with full control over the specs. Not plant. Not animal. Something else." Additional laws Authors other than Asimov have often created extra laws. The 1974 Lyuben Dilov novel, Icarus's Way (a.k.a., The Trip of Icarus) introduced a Fourth Law of robotics: "A robot must establish its identity as a robot in all cases." Dilov gives reasons for the fourth safeguard in this way: "The last Law has put an end to the expensive aberrations of designers to give psychorobots as humanlike a form as possible. And to the resulting misunderstandings..." A fifth law was introduced by Nikola Kesarovski in his short story "The Fifth Law of Robotics". This fifth law says: "A robot must know it is a robot." The plot revolves around a murder where the forensic investigation discovers that the victim was killed by a hug from a humaniform robot that did not establish for itself that it was a robot. The story was reviewed by Valentin D. Ivanov in SFF review webzine The Portal. For the 1986 tribute anthology, Foundation's Friends, Harry Harrison wrote a story entitled, "The Fourth Law of Robotics". This Fourth Law states: "A robot must reproduce. As long as such reproduction does not interfere with the First or Second or Third Law." In 2013 Hutan Ashrafian proposed an additional law that considered the role of artificial intelligence-on-artificial intelligence or the relationship between robots themselves – the so-called AIonAI law. This sixth law states: "All robots endowed with comparable human reason and conscience should act towards one another in a spirit of brotherhood." See also Friendly AI Roboethics Ethics of artificial intelligence Military robots which may be designed such that they violate Asimov's First Law. Three Laws of Transhumanism Clarke's three laws Niven's laws References Robotics