In 1795, a 43-year-old professor from Göttingen, Germany, was five years into a new and exciting scientific project. His name was Johann Friedrich Blumenbach. Blumenbach may not be a familiar name today, but back then among men of letters he was already established as an eminent physiologist and natural philosopher. He was editor of the Medicinische Bibliothek and author of a widely-circulated anatomy text Institutiones Physiologicae, which explored and explained the little details of animal anatomy.
The project of Blumenbach's was something unseen to natural science at the time, an idea of his own. Blumenbach scoured the earth for the skulls of humans from different people groups to draw conclusions about racial and enthographic differences. It was the start of comparative anatomy across human groups.
Blumenbach began his work in 1790, halfway through a stay in England, and by 1795 he had amassed no fewer than 60 craniums, representing peoples around the globe. The skulls came from as near as Holland and as far as northernmost North America. Most exciting to Blumenbach, however, was a skull from the Georgian people. Why was Georgian most exciting?
Blumenbach had a perverted sense of beauty, where what was beautiful to him was equivalent to some sort of biological truism. Typical of the time, he valued the high vertical forehead of northern Eurasians, pronounced eye ridges, and Roman jawline. Nowhere were these qualities more strikingly found, Blumenbach saw, than among the Kartvelian people - Georgians.
Now Blumenbach was not studying these skulls in an historical vacuum, free from the influence of those before him. Blumenbach's comparisons of skulls were made to advocate that all humans come from a single parentage (the Biblical Adam and Eve) and to refute the earlier argument of Christoph Meiners' that different races came from separate sources. Five years into his project, Blumenbach had concluded that the study of skulls was strong evidence that all humans are related, by asserting that the differences were gradations of changes. In other words, by studying all human skulls, we see a spectrum of change across the world and no single marked differences among races.
But his work of 18th-century science was fraught with 18th-century nonsense. He praised the Georgian skulls as the most beautiful and, because beauty was an indication of perfection, argued in that same work that all humans come from the Caucasus, the homeland of the Georgians. Because white Eurasians (the whole of Europeans but also Turks and Hindustani) best "preserve" the features of their putative ancestors, they were Caucasian. Other large racial groups he called Ethiopian, Mongoloid, Americanoid, and Malay.
Blumenbach's work was published in Latin under the title Collectionis suae craniorum diversarum gentium illustratae decades later that year and it was well received by the scientific community. His term "Caucasian" as a moniker for all white people stuck. That is the origin of why we call all white people Caucasian, despite only a small subset of people truly coming from the Caucasus.
Blumenbach didn't coin the word Caucasian. Christoph Meiners invented it in 1785 (from the Latin name for the region), but it was only when Blumenbach borrowed the word from Meiners that the name spread.
How are we to judge Blumenbach's work today? Blumenbach's work was piece of both racism and progressive values. As I discussed, Blumenbach erroneously based his scientific conclusions in part on his conviction that what was beautiful to him was somehow purer. This led Blumenbach down many dark paths over his career. As Bhopal (2007) noted, Blumenbach dismissed diseases that cause a loss of skin pigment like leucoplakia as a fiction, because lighter skin was more beautiful to him. In his mind, leucoplakia was a return to a more natural physical state.
On the other hand, Blumenbach confronted the racist values of the time. He believed all races were equal in intelligence and rationality (Stephen Jay Gould notes that he was remarkably insistent of the fact of equal human worth), albeit not as objectively beautiful. His work refuted the consensus of his contemporaries that whites were completely unrelated to other races. So while Blumenbach's views are disappointingly backwards by today's standards, they are happily forward-thinking for his day and age. It's dangerous to assume that Blumenbach would hold his racialist views had he been born in a time of greater scientific enlightenment.
Later scientists, both "psuedo" and legitimate, hijacked Blumenbach's comparative anatomy of skulls and used the differences in skull size and shape across human ethnic groups to determine differences in intelligence. Samuel Morton was most infamous for this. Of course, it's all hogwash. Outside of rare genetic disorders, skull size and shape are superficial and not an indication of intelligence.
Today, Blumenbach is largely forgotten. But his hallmark is a permanent indent upon the English language, the history of the word Caucasian. For more reading, see:
Bhopal, Raj. "The beautiful skull and Blumenbach's errors: the birth of the scientific concept of race." BMJ. (2007).
"Race - The Power of an Illusion." Interview with Stephen Jay Gould. PBS. California Newsreel. (2003).
Other works mentioned here are:
Blumenbach, Johann Friedrich. Collectionis suae craniorum diversarum gentium illustratae decades. (1790-1828)
Meiners, Christoph. Grundriß der Geschichte der Menschheit. (1785).