Any technology that does not appear magical is insufficiently advanced.

This is derived from the third of Arthur C. Clarke's three laws : "Any sufficiently advanced technology is indistinguishable from magic." There are other variants which had inverted this including one known as Gehm's corollary, published several years earlier : "Any technology distinguishable from magic is insufficiently advanced." The earliest variant seems to be "Any sufficiently advanced magic is indistinguishable from technology." It has been called "Niven's Law" and attributed to Larry Niven by some, and to Terry Pratchett by others, but without any citation of an original source in either case — the earliest occurrence yet located is an anonymous one in Keystone Folklore (1984) by the Pennsylvania Folklore Society.