The Flash of Genius Doctrine or Flash of Genius Test was a test for patentability used by the United States Federal Courts for over a decade. The doctrine was formalized in Cuno Engineering Corp. v. Automatic Devices Corp. (314 U.S. 84 (1941)) which held that the inventive act had to come into the mind of an inventor in a "flash of genius" and not as a result of tinkering. "The new device, however useful it may be, must reveal the flash of creative genius, not merely the skill of the calling. If it fails, it has not established its right to a private grant on the public domain." (Id. at 91). This test, which lasted little more than a decade, was most likely an appealing and easy standard for judges and unsophisticated jurors to apply to any given patent dispute when the technology being disputed was beyond their non-scientific acumen.
The flash of genius test was eventually rejected by the 1952 patent statute's Section 103 standard of non-obviousness: "Patentability shall not be negatived by the manner in which the invention was made." Many decades later, the United States Court of Appeals for the Federal Circuit stated that this portion of Section 103 was enacted expressly to overrule the flash of genius test from Cuno (Ryko Manufacturing v. Nu-Star, Inc., 950 F.2d 714, 718 (Fed. Cir. 1991)).