The German Genius

mechanism of natural selection was identified, many biologists (Lamarck was one) argued for the existence of nonphysical (even nonmaterial) forces that drive the living world “upward toward ever greater perfection.” 31 This was known as orthogenesis. Leibniz, Linnaeus, Herder, and almost all British scientists shared this view, some of them as late as the middle of the nineteenth century.
    So, from the middle of the sixteenth to the middle of the nineteenth century, two schools of thought coexisted: the physical scientists believed that God, at the time of the Creation, had instituted eternal laws governing the processes of this world (essentially the deist view). Against that, devout naturalists—familiar with living nature—concluded that, so far as the diversity and myriad adaptations of living creatures are concerned, the mathematically based laws of Galileo and Newton were meaningless. 32 Germany was one of the main centers of this latter group.
    Within biology (to use the modern term), a new era of observation had begun with the work of the so-called German fathers of botany—Otto Brunfels (1488–1534), Hieronymus Bock (1489–1554), and Leonhart Fuchs (1501–66). The study of medicinal plants was popular throughout the later Middle Ages and was reflected in the publication of a number of herbals. Then, as a result of the great voyages in the age of exploration and the discovery of the New World, the immense variety of plant and animal life across the globe was realized. 33 These German botanists provided a break from medieval works, which were endlessly copied myths and allegories. Instead, their descriptions were based on real plants observed in their natural habitat, with the result that their realistic drawings played much the same role in botany as those of Vesalius did in anatomy. Hieronymus Bock’s descriptions—in meticulous if colloquial German—were vividly drawn from his own observations. Importantly, he also broke with the alphabetical arrangements of earlier herbals, describing instead his own method “to place together, yet to keep distinct, all plants which are related and connected, or otherwise resemble one another.” 34 The German herbals are worth singling out because of the new classificatory principles they introduced. This early tradition of classification reached its climax in 1623 with the release of Caspar Bauhin’s Pinax , in which 6,000 kinds of plants were arranged in twelve books and seventy-two sections. 35 Related plants were often put together because of their common properties, and each plant assigned to a genus and a species, though genera were not defined. In addition, there was in Pinax an implicit separation of the monocotyledons, and some nine or ten families of dicotyledons were brought together also. Already, reproduction was recognized as crucial.
    Botanists from Conrad Gesner (1567) and Andrea Cesalpino (1583) to Linnaeus all recognized the importance of fructification for classification, but this still left great scope for argument owing to the multitude of characteristics available, all bearing on fructification. 36 Debate was and was not helped by the fact that the number of known plants increased at an astonishing rate during the sixteenth and seventeenth centuries. In 1542, Leonhart Fuchs identified some 500 species, Bauhin in 1623 referred to 6,000 species, while John Ray in 1682 listed no fewer than 18,000. 37 The need for order and classification was greater than ever, but the welter of new material was overwhelming. At much the same time, while all others around him were fixated on the concept of essentialism (according to which each species is characterized by its unchanging essence— eidos —and separated from all other species by a sharp discontinuity), Leibniz stressed the opposite: continuity. Ernst Mayr, the German-born Harvard historian of biology, argues that Leibniz’s interest in the scala naturae , and the links between various life forms (as revealed in the earliest attempts at plant classification), helped prepare the ground for Linnaeus and, ultimately, for evolutionary thinking.
    A key figure here was Albrecht von Haller (1707–77) who began a number of wide-ranging animal experiments, examining the operation of various internal organs. Haller found no evidence for a “soul” governing physiological functions, but his studies did convince him that bodily organs have certain properties (irritability, for example) which are