For two years in the late 1970s I followed in the footsteps of Carl Linnaeus: I toiled in the field of taxonomy. The small corner of nature’s jigsaw I tackled was a group of New Zealand marine sponges whose baffling variability defied easy classification. I considered their colour and form, examined their skeletal architecture, counted their spicules, noted the shape of their larvae, and pondered which of these characters could be used to separate my subjects into meaningful categories.

The result of my labours was a classification scheme for 43 species of sponge—an achievement of near insignificance when placed alongside that of Linnaeus, who in the course of his life classified and named more than 4000 animals and nearly 8000 plants. As superhuman a feat as that was, the illustrious Swede also invented the system of classification that every student of taxonomy, myself included, has used since.

The eldest son of a small-town curate and expected to follow that calling, Linnaeus chose instead to pursue his father’s recreational interest in plants and became the greatest botanist of his time. He was also a successful physician (attending Swedish royalty), a charismatic lecturer, a devoted mentor, an enthusiastic gardener and a prolific writer. He not only sorted and systematised all the known species of his day, but also pioneered the study of how indigenous people use plants for medical and other purposes, earning the sobriquet “father of ethnobotany”. The simplicity and logic of his taxonomic system made natural history accessible to amateurs, ushering in the Victorian passion for nature. Jean Jacques Rousseau said of him, “I know no greater man on earth.”

It is as a taxonomist that Linnaeus is chiefly remembered. His genius was to apply the social hierarchy of his time, with its kingdoms, provinces, parishes and villages, to the natural world. He slotted plants and animals into a hierarchy of categories, each nesting like a Russian doll within the next. His sequence—species, genus, order, class, kingdom—is still in use, augmented by a still-expanding bevy of additional gradations, such as subspecies, tribe, family, phylum and, more recently, phalanx, infracohort and supertribe.

Almost incidental to Linnaeus’s encyclopaedic audit of the natural world was his decision to call each living thing by just two Latin names, representing the genus and the species. Yet this innovation, known as binomial nomenclature, has proved to be his greatest gift to posterity. Any time Homo sapiens or Felix domestica—or, in my case, Callyspongia ramosa—is mentioned, Linnaeus’s naming system is invoked.

Before Linnaeus, the naming of organisms was a shambles. There were multiple names for even the commonest species, and as many criteria for classifying them as there were scientists doing the classification. Instead of Linnaeus’s concise, double-barrelled binomials there were wordy polynomials composed of a dozen or more terms—descriptions more than names. The tomato, for example, was Solanum caule inermi herbaceo, foliis pinnatis incises—the solanum with the smooth stem which is herbaceous and has incised pinnate leaves. Out of a Babel of complicated, competing nomenclatures Linnaeus forged a single, universally applicable scientific language. For this he has been likened to Hercules, bringing order to the Augean stables of natural history.