You Could Look It Up (8 page)

Theophrastus had no conception of evolution or genetics, and he had to depend on naked-eye observation to see the deep connections. His task was even more difficult than classifying animals, because the features and behaviors of plants are less obvious to the untrained eye. The fact that some flowers are white, some pink, and some blue is merely accidental—they could just as easily be other colors—so a biological taxonomist should not make flower color an essential part of classification. Which qualities, though, do make each plant species what it really is? Should we put all the flowering plants in one group,
the nonflowering plants in another? Keep the woody stems together? Are the grasses a distinct kind, or do many essentially different plants happen to look grassy?

Before Theophrastus, most plant classifications were based on human needs: plants were grouped based on their use as food or medicine, whether they were wild or cultivated, and so on. Theophrastus took a different approach and based his taxonomy on morphology or form. He used physical structure to define his four broadest categories: tree, shrub, half-shrub, and herb. He then went on to divide species all into flowering and nonflowering species—still an important distinction in botany. He went even further, dividing the flowering species into those with leafy flowers and those with capillary flowers, laying the groundwork for much later breakthroughs in petaliferous and apetalous flowers. He made important discoveries in the structure of flowers, though he did not understand that flowers were plants’ reproductive organs. A master of close observation, Theophrastus described the minute structures of small seeds at a time when even the magnifying glass was unknown. Still he described plant morphology, from root to fruit, in more detail than anyone before him, distinguishing permanent from transient features of plant biology.

The structure of
Historia plantarum
reflects this taxonomic understanding. Book 1 covered the anatomy of plants, including roots, fruits, seeds, leaves, flowers, and other parts. It lays out his four broad categories, while acknowledging there were complex cases that would test his boundaries. Book 2 moves on to the growth of plants from seeds, bulbs, or roots. Book 3, on wild trees, corrects conventional wisdom by insisting that trees do not emerge from spontaneous generation. In book 4, Theophrastus examines foreign trees and shrubs, with attention to the wider Mediterranean world. Wood in its many varieties is the subject of book 5, shrubs of book 6, small herbs of book 7, and cereals, beans, and peas of book 8. In his discussion of woods he describes which ones are best suited to timber and which ones work well in a lathe. Book 9 is devoted entirely to the use of plants as medicines, making it one of the oldest surviving herbals. Theophrastus did his best to sort reliable fact from superstition, and the result is a magisterial survey of the entire plant kingdom as it was known in fourth-century-
B.C.E.
Greece. It touches on
more than five hundred plant species, the large majority of which are cultivated rather than wild plants—he says that most wild plants cannot be discussed because they have been neither identified nor named. Still, he was the first to recognize the existence of aerial roots, which are common in orchids, mangroves, banyan trees, and other species.

Scholars believe Theophrastus intended his work as a set of lecture notes, but before long it was being employed as a reference book. The entries are curt and include quick lists of related plants or features, designed for easy consultation. Almost any ancient investigator into the plant kingdom would begin with Theophrastus, navigating through his taxonomy and finding a specimen’s place in the larger scheme. And this decision to reduce the botanical world to a work of reference had lasting consequences. Because he devoted so much effort to a logical organization, one that was structured around the plants themselves rather than around human needs, his reference book served to turn attention outward to the natural world. He made the gathering of further information possible, because his collection revealed clearly where the gaps in knowledge were and signaled to the world where research might profitably proceed. Though Theophrastus’ work was lost and forgotten through most of the Middle Ages, its rediscovery at the beginning of the fifteenth century led to a series of editions and translations at just the time the West was beginning its scientific revolution.
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Theophrastus’ knowledge was daunting, but his most important successor in the ancient world makes even his polymathic range seem limited.

Gaius Plinius Secundus, better known as Pliny the Elder, was born in 23
C.E.
at Como in the Italian Alps. He was schooled in Rome, by then as much the center of the intellectual world as Athens had been three and a half centuries earlier. Christianity was in its very earliest phases, and there is no evidence that it made any impression on Pliny. But Rome in the thirties and forties
C.E.
was a literary hot spot. Roman politics in the era was notoriously messy: the emperor Tiberius, who had effectively walked away from his duties after a coup, died in the year 37, leaving his great-nephew Caligula to become emperor; he was in turn assassinated after just four years. His uncle, Claudius, would
take over until his own death in 54, when he was succeeded by his adopted son Nero.

This was the background to Pliny’s life, and the political turmoil was more relevant to his career than such things usually are for scientists. Pliny was above all a man of the world. He commanded a cavalry squadron in Germany, Gaul, and Spain. He was a friend and confidant of generals, politicians, even emperors. He was at the center of political and military power in the early Empire. Still he found time to write. Only one of his works survives, but we are lucky to have a reliable list of all the others, because he cataloged his life’s work in a letter to a friend: seven works, coming to a total of 102 scrolls (
libri
in Latin). He wrote on military matters, on grammar, and on Roman history, and he was an amazingly disciplined writer. Pliny’s nephew, also called Pliny, preserved this account of his uncle at work, describing his “keen intelligence, incredible devotion to study, and a remarkable capacity for dispensing with sleep.” The uncle would get up “long before daybreak” and work until two o’clock the next morning, pausing in his studies only to pay a visit to the emperor Vespasian. That devotion to his work was evident in everything he did: his only downtime was while he was in the bath, and even then he would have someone read to him. The same regime was in place at the dinner table:

Over his dinner a book was read aloud to him and notes were made, and that at a rapid pace. I remember that one of his friends, when the reader had rendered a passage badly, called him back and had it repeated; but my uncle said to him, “Surely you got the sense?” and on his nodding assent continued, “Then what did you call him back for? This interruption of yours has cost us ten more lines!” Such was his economy of time.

A traveling secretary read to him on the road, and he even chided his nephew for walking anywhere in Rome: had he taken a sedan chair, he could have used the time to do more reading. As his nephew summarized his guiding philosophy, “He thought all time not spent in study wasted.”
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Though Pliny read and wrote widely, he seems to have had scientific interests throughout his life.
Historia naturalis
means “natural history,”
though the phrase usually means what we would think of as the observational sciences generally. As Tom McArthur wrote,
Historia naturalis
“could just as easily be interpreted in modern terms as
General Knowledge
.”
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Pliny and his readers would not have understood the fields he covered as part of some broader enterprise called “science”; they would have been more comfortable with the idea of “nature.” As a twentieth-century translator puts it, the
Historia
is “an encyclopaedia of astronomy, meteorology, geography, mineralogy, zoology, and botany,
i.e.
a systematic account of all the material objects that are not the product of man’s manufacture.”
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