][citation needed] Historians and sociologists have remarked the occurrence, in science, of "multiple independent discovery".
Robert K. Merton defined such "multiples" as instances in which similar discoveries are made by scientists working independently of each other.
"[4][page needed][6] Commonly cited examples of multiple independent discovery are the 17th-century independent formulation of calculus by Isaac Newton, Gottfried Wilhelm Leibniz and others;[7][page needed] the 18th-century discovery of oxygen by Carl Wilhelm Scheele, Joseph Priestley, Antoine Lavoisier and others;[citation needed] and the theory of evolution of species, independently advanced in the 19th century by Charles Darwin and Alfred Russel Wallace.
[10] Multiple independent discovery and invention, like discovery and invention generally, have been fostered by the evolution of means of communication: roads, vehicles, sailing vessels, writing, printing, institutions of education, reliable postal services,[12] telegraphy, and mass media, including the internet.
This may accord with the thesis of British philosopher A.C. Grayling that the 17th century was crucial in the creation of the modern world view, freed from the shackles of religion, the occult, and uncritical faith in the authority of Aristotle.
Grayling speculates that Europe's Thirty Years' War (1618–1648), with the concomitant breakdown of authority, made freedom of thought and open debate possible, so that "modern science... rests on the heads of millions of dead."
He also notes "the importance of the development of a reliable postal service... in enabling savants... to be in scholarly communication.... [T]he cooperative approach, first recommended by Francis Bacon, was essential to making science open to peer review and public verification, and not just a matter of the lone [individual] issuing... idiosyncratic pronouncements.
[13][page needed] Lamb and Easton, and others, have argued that science and art are similar with regard to multiple discovery.
By June 1858 Charles Darwin had completed over two-thirds of his On the Origin of Species when he received a startling letter from a naturalist, Alfred Russel Wallace, 13 years his junior, with whom he had corresponded.