  What are the connections to Leibniz’s logic? Are there anticipations of the Boolean calculus in the work of Leibniz? One of those authors looking for anticipations was Robert Leslie Ellis (1817–1859), who edited Francis Bacon’s Novum Organon in The Works of Francis Bacon (1858–1874; vol. 1: 1858). During his editorial works he found a parallel to Boole’s Law (p. 281, footnote 1): “Mr. Boole’s Laws of Thought contain the first development of ideas of which the germ is to be found in Bacon and Leibnitz; to the latter of whom the fundamental principle in logic a2 = a was known.” As reference he gave Erdmann’s edition (Erdmann 1840, p. 130). Robert Harley (1828–1910), Boole’s first biographer, discussed this information in a paper entitled “Remarks on Boole’s Mathematical Analysis of Logic” (1867). He did not find the proper quote at the place indicated by Ellis, but he found other relevant texts. About the significance of Ellis’ remark he wrote: “Boole did not become aware of these anticipations by Leibnitz until more than twelve months after the publication of the ‘Laws of Thought,’ when they were pointed out to him by R. Leslie Ellis” (p. 5).