If you read a thumbnail biography, in an encyclopedia or on a website, you're liable to be told that Carl Linnaeus was "the father of taxonomy"—that is, of biological classification—or that he created the Latin binomial system of naming species, still used today. Those statements are roughly accurate, but they don't convey what made the man so important to biology during his era and afterward. You might read that he coined the name Homo sapiens for our own species and placed us, daringly, within a category of mammals that included monkeys and apes. That's true too, but somewhat misleading. Linnaeus was no full-blown evolutionist. On the contrary, he heartily embraced the prevailing creationist view of biological origins, which stipulated that studying nature reveals evidence for the creative powers and mysterious orderliness of God. He wasn't such a pious man, though, that he sought nothing but godliness in the material world. Here's what makes him a hero for our time: He treasured the diversity of nature for its own sake, not just for its theological edification, and he hungered to embrace every possible bit of it within his own mind. He believed that humankind should discover, name, count, understand, and appreciate every kind of creature on Earth.
In order to assemble all that knowledge, two things were required: tireless and acute observation, and a system. In spring of 1732, just before his 25th birthday, Linnaeus set off on an expedition through Lapland, the wild northern region of the Swedish kingdom, inhabited by a sparse population of the Sami people, who lived as herders of reindeer. Over the next five months he traveled some 3,000 miles (4,800 kilometers), by horseback and foot and boat, making collections and taking notes as he went. He was interested in everything—birds, insects, fish, geology, the customs and technology of the Sami—but especially in plants. He made drawings in his journal, some of which were crude sketches, some of which (again, those of plants) were delicate and lovingly precise. Eventually, he produced a book, Flora Lapponica, describing the botanical data he had gathered.
He went abroad in 1735 to advance his career prospects. He spent three years on the Continent, mostly in Holland, taking a medical doctor's degree quickly, then turning back to plants.
It wasn't a stretch to combine both activities, since botany in that era was considered a branch of medicine, through the pharmaceutical uses of vegetation. He found temporary work with a rich man named George Clifford, a director of the Dutch East India Company, as botanical curator and house physician at Clifford's country estate near Haarlem. Linnaeus's work there led to another book, a descriptive catalog of Clifford's botanical holdings, titled Hortus Cliffortianus and gorgeously illustrated by a young artist named Georg Dionysius Ehret. Although they became lifelong friends, Ehret later recalled the Linnaeus of these years as a self-aggrandizing opportunist. By any account, he was full of energy and plans, full of ideas and opinions, and hungry for success as well as for deeper knowledge. Confident to the point of arrogance but charming enough to compensate, he proved good at making friends, finding sponsors, and cultivating powerful contacts. During the three years abroad he published eight books—an amazing spurt of productivity, partly explained by the fact that he had left Sweden carrying some manuscripts written earlier. One of those manuscripts became Systema Naturae, now considered the founding text of modern taxonomy.
Linnaeus wasn't the first naturalist to try to roster and systematize nature. His predecessors included Aristotle (who had classified animals as "bloodless" and "blooded"), Leonhart Fuchs in the 16th century (who described 500 genera of plants, listing them in alphabetical order), the Englishman John Ray (whose Historia Plantarum, published in 1686, helped define the species concept), and the French botanist Joseph Pitton de Tournefort, contemporary with Ray, who sorted the plant world into roughly 700 genera, based on the appearance of their flowers, their fruit, and their other anatomical parts.