Carl Von Linnaeus: Scientific Classification of Human Races in Systema Naturae

In 1758, a Swedish botanist sat down to update his catalogue of the natural world and, in the process, gave racism a scientific-sounding vocabulary that would outlive him by centuries. Carl von Linnaeus is remembered today as the father of modern taxonomy, the man who gave us the neat system of genus and species we still use for every living thing. But tucked inside his most famous book, Systema Naturae, is one of the earliest attempts to sort human beings into biological categories based on skin colour and character. For students of biological anthropology, this classification matters not because it was accurate, but because of how much damage a confident, “scientific” label can do when it is wrong.

Who was Carl Linnaeus? 🔗

Linnaeus was a Swedish physician and naturalist who spent his career trying to bring order to the natural world. His system of binomial nomenclature, giving every organism a two-part Latin name such as Homo sapiens, is still the backbone of biological classification today. He first published Systema Naturae in 1735 as a slim, eleven-page pamphlet, and kept expanding it across twelve editions over his lifetime. By the time he reached the tenth edition in 1758, the entry on humans had grown into five detailed pages, and it is this edition that historians consider the true starting point of scientific racial classification.

The first sketch: four varieties by geography 🔗

In the earliest editions of his work, Linnaeus divided humans into four simple varieties, each tied to a continent and a skin tone: Europaeus albesc (white), Americanus rubesc (red), Asiaticus fuscus (dark), and Africanus nigr (black). At this stage, the classification was fairly restrained. Linnaeus focused almost entirely on geography, and his reasoning followed the popular climate theory of the time, the idea that skin colour was an external, environmental trait shaped by sun and climate rather than something fixed and essential. In this sense, the earlier editions were closer to a simple sorting exercise than a value-laden hierarchy.

The tenth edition: race gets a personality 🔗

Everything changed in 1758. Linnaeus was already using a system of six classes for humans, but in the tenth edition he layered on something new: temperament. Drawing on the ancient medical theory of the four humours, sanguine, choleric, melancholic, and phlegmatic, he assigned each human variety a personality type, a set of physical traits, and even a description of clothing and government. What had been a geographic sorting system now carried moral and behavioural judgements. This is the point where, as the Uppsala University researchers who study his legacy put it, Linnaeus moved from pure environment to evaluation, and the descriptions stopped being neutral.

It is worth noting that this same edition also included categories like Homo monstrosus and Homo ferus, groupings based on travellers’ tall tales and mythical “wild men.” Their presence is a useful reminder that Linnaeus was not working from rigorous fieldwork. He was compiling secondhand reports, personal assumptions, and prevailing European prejudice, and presenting all of it inside the same authoritative scientific framework he used for plants and animals.

The four geographical races and their traits 🔗

The 1758 classification described four main human varieties, each combining skin colour, humoral temperament, personality, and a description of how the group was supposedly governed.

Homo Europaeus 🔗

Described as white, sanguine, and muscular, Linnaeus called this group fickle, gentle, and inventive. Crucially, he wrote that Europeans were governed by laws, the most flattering of the four descriptions and, unsurprisingly, the group Linnaeus himself belonged to.

Homo Asiaticus 🔗

This group was labelled sallow or yellow, melancholic, and stiff. Linnaeus described the temperament as grave, haughty, and avaricious, and said the group was ruled by opinions.

Homo Americanus 🔗

Indigenous peoples of the Americas were described as reddish, choleric, and obstinate, associated with a contented but stubborn disposition, and said to be regulated by custom.

Homo Afer (Africanus) 🔗

Africans were described as black and phlegmatic, and given the harshest characterisation of the four: cunning, lazy, and careless, governed by caprice, a word implying impulsiveness rather than reason or order.

Read together, the four descriptions form a clear scale, from law, to opinion, to custom, to caprice. That is not a coincidence. It reflects, almost point for point, an ordering of who Linnaeus considered rational and civilised, and who he did not.

The great chain of being: a hidden hierarchy 🔗

Linnaeus never wrote out an explicit ranking of “best to worst” human variety. But the structure of his descriptions was shaped by an older idea circulating in European thought: the great chain of being, or scala naturae, a Judeo-Christian concept that pictured all of creation arranged on a single ladder, from the simplest organisms up through humans, angels, and God. Enlightenment thinkers who wanted to justify colonialism and slavery found this ladder useful, because it implied that inequality among humans was simply part of the natural order. Some intellectuals of the period revived this framework specifically to argue that nature, or God, had made humanity unequal by design.

Linnaeus’s four varieties fit neatly into this mindset. By placing law-abiding Europeans at one end and “capricious” Africans at the other, his classification implied a descending scale of reason and civilisation, even without stating a formal hierarchy in so many words. The scientific packaging made the bias harder to spot and, therefore, more dangerous.

Why the classification was scientifically and ethically flawed 🔗

From a modern biological anthropology perspective, this system fails on several counts. First, it confused biology with culture, mixing observations of skin colour with judgements about behaviour, government, and morality, categories that have nothing to do with human genetics. Second, it treated character traits as fixed and inherited, when personality and social organisation are shaped by history, environment, and circumstance, not skin tone. Third, and most importantly, it was built on almost no direct evidence. Linnaeus never conducted anthropological fieldwork among the populations he described; he relied on the biased travel writing and hearsay available to an eighteenth-century European scholar.

Researchers who study his work today generally avoid two extremes. They resist the label of Linnaeus as the sole “father of scientific racism,” since the idea of race as a natural hierarchy developed gradually through many thinkers, but they also reject the defence that he was simply “a man of his time” with no lasting responsibility. As the Uppsala researchers argue, both the credit and the blame need to be shared across a wider historical process, of which Linnaeus was an influential part, not the entire story.

The legacy: from Linnaeus to nineteenth-century race science 🔗

Whatever Linnaeus’s personal intentions, his taxonomy gave later scholars a template. Once human variation was sorted into a scientific-looking table with Latin names, it became easy for nineteenth-century thinkers to add craniometry, skull measurements, and other pseudoscientific tools on top of it, building what came to be called scientific racism. A detailed history of this taxonomy notes that Linnaeus’s four-way division tapped into an existing European habit of organising the world into sets of four, continents, elements, humours, and made race feel like just another natural category rather than a social invention. Later naturalists cited Linnaeus’s authority to support increasingly rigid and harmful ideas about biological difference, even though taxonomists studying his original naming point out that his subspecies names described anecdotal, often prejudiced, behavioural stereotypes rather than any real biological boundary.

Modern biological anthropology has moved decisively away from this framework. Genetic research shows that human variation does not sort neatly into a handful of discrete races; there is more genetic diversity within so-called racial groups than between them. Skin colour, in particular, is now understood as a trait shaped by generations of adaptation to sunlight exposure, not a marker of intelligence, temperament, or moral character. Studying Linnaeus’s classification today is less about learning “correct” categories and more about understanding how easily bias can be dressed up as objective science, and why anthropologists remain cautious about any system that ranks human groups.

What do you think? If a respected scientist today built a classification system using cultural stereotypes instead of evidence, would we recognise the bias as quickly as we do with Linnaeus, or does distance in time make it easier to see? And how much responsibility should we place on Linnaeus personally, versus the broader European mindset he was writing within?

References

1. https://www.linnean.org/research-collections/on-display/homo-sapiens-classifying-the-human-animal
2. https://www.linnean.org/learning/who-was-linnaeus/linnaeus-and-race
3. https://www.linnean.org/learning/who-was-linnaeus/linnaeus-and-race-easy-read
4. https://www.uu.se/en/news/2021/2021-05-07-linnaeus-complicated-relationship-with-racism
5. https://www.britannica.com/topic/scientific-racism
6. https://www.sapiens.org/biology/race-scientific-taxonomy/
7. https://www.researchgate.net/publication/260337719_Who_is_the_type_of_Homo_sapiens