One of the recurrence patterns identified by G.W. Trompf involves "the isolation of any two specific events which bear a very "striking similarity"". The Spanish-American philosopher George Santayana observed that "Those who cannot remember the past are condemned to repeat it." Karl Marx, having in mind the respective coups d'état of Napoleon I (1799) and his nephew Napoleon III (1851), wrote acerbically in 1852: "Hegel remarks somewhere that all facts and personages of great importance in world history occur, as it were, twice. He forgot to add: the first time as tragedy, the second time as farce."