During the nineteenth century, archaeologists had little idea about the distinctions between deliberately chipped stone (tools and the waste material, known as débitage) and those that had been fractured by natural processes, such as frost or mechanical shattering. The issue became controversial after an amateur collector, Benjamin Harrison (1837-1921), found numerous pieces of chipped flint in Kent (England) in 1885. The geologist Sir Joseph Prestwich (1812-1896) published these discoveries in 1891, citing them as evidence for humans in the Pliocene (5.3 to 1.8 million years ago), as that was the age of the deposit in which Harrison had found them. There was general acceptance of the discovery and in 1892, John Allen Brown (1831-1903) devised the term eolith (Greek for ‘dawn stone’) to describe them. Over the next three decades or so, numerous assemblages of eoliths were found throughout the world, but especially in England.

Nevertheless, there were objectors. In 1892, George Worthington Smith (1835–1917), dismissed them, while the French prehistorian Marcellin Boule (1861-1942) published a paper in 1905 arguing that eoliths were geofacts, objects modified by natural processes rather than early hominids. A little later, the English amateur Samuel Hazzledine Warren (1873-1958) demonstrated that eoliths were indistinguishable from those he produced by mechanical means, such as rolling in a metal drum. The debate was at times acrimonious, with James Reid Moir (1879-1944), an enthusiastic supporter of their artificiality, discovering and promoting collections throughout East Anglia (England), the area where S Hazzledine Warren was working.

Marianne Sommer has shown how much of the debate was conducted in implicitly nationalistic terms: while there was little acceptance of Pliocene tools in France, where it was generally believed that this was too early for humans, they were enthusiastically received in England as evidence for early hominids in Britain. It should be remembered that most of the very limited lithic material associated with the forged Piltdown remains (dubbed “The First Englishman” by the English press) consisted of eoliths: the eoliths were taken as evidence confirming the age of the remains, while the remains were taken as evidence that eoliths were artefacts. Ironically, the likely forger of the Piltdown material, Charles Dawson (1864-1916), did not believe in eoliths and delivered a paper in 1915 during which he demonstrated that shaking a bag filled with starch models of flint would produce “all the well-known eolith shapes” purely by mechanical means.

By the late 1930s, it was generally accepted that eoliths are geofacts and are not evidence for Pliocene hominids in Europe. This happened for two reasons: firstly, there was the demonstration that their characteristics were entirely consistent with natural formation processes and secondly, no well-dated Pliocene hominid fossils were ever found in Europe and those in Africa produced a completely different type of tool, belonging to the Oldowan tradition.