Charles Darwin did not mention Monboddo, but commented on Buffon: "the first author who in modern times has treated [evolution] in a scientific spirit was Buffon". Buffon thought that man was a species unrelated to lower primates, but Monboddo rejected Buffon's analysis and argued that the anthropoidal ape must be related to the species of man: he sometimes referred to the anthropoidal ape as the "brother of man". Monboddo suffered a setback, in his standing on evolutionary thought, because he stated at one time that men had caudal appendages (tails); some historians failed to take him very seriously after that remark, even though Monboddo was known to bait his critics with preposterous sayings. Bailey's The Holly and the Horn states that "Charles Darwin was to some degree influenced by the theories of Monboddo, who deserves the title of Evolutionist more than that of Eccentric." Henderson says: "He [Monboddo] was a minor celebrity in Edinburgh because he was considered to be very eccentric. But he actually came up with the idea that men may have evolved instead of being created by God. His views were dismissed because people thought he was mad, and in those days it was a very controversial view to hold. But he felt it was a logical possibility and it caused him a great deal of consternation. He actually did not want to believe the theory because he was a very religious person." Monboddo may be the first person to associate language skills evolving from primates and continuing to evolve in early humans (Monboddo, 1773). He wrote about how the language capability has altered over time in the form not only of skills but physical form of the sound producing organs (mouth, vocal cords, tongue, throat), suggesting he had formed the concept of evolutionary adaptive change. He also elaborates on the advantages created by the adaptive change of primates to their environment and even to the evolving complexity of primate social structures. In 1772 in a letter to James Harris, Monboddo articulated that his theory of language evolution (Harris 1772) was simply a part of the manner that man had advanced from the lower animals, a clear precedent of evolutionary thought. Furthermore, he established a detailed theory of how man adaptively acquired language to cope better with his environment and social needs. He argued that the development of language was linked to a procession of events: first