Changing Ways of Thinking About Plants

Academicians thought of research on plants as being of two types: descriptive natural history (l'histoire ), which will be discussed in chapters 6

through 8, and explanatory natural philosophy (la physique ), which will be discussed in chapters 9 through 12.

The concept of natural history goes back at least to Aristotle, whose Historia animalium lays out what its author knows about animals, organizing that knowledge into such categories as number and type of limbs, mechanisms for eating, and mode of reproduction. Aristotle offers a series of generalizations, each modified by exceptions and strengthened by comparisons. Subsequent natural histories always contained these two elements: they enumerated the pertinent facts and they generalized in order to organize the facts. Aristotle's book introduced his treatises on the functions of the various parts of the body, reproduction and generation, and other aspects of a natural philosophy of animals. It was the necessary preliminary to causal analysis. But the blend of assumption and generalization in Aristotle's work, as in the natural histories of later authors, betrays a pattern of causal thought embedded in the method itself.

Surveying the two-thousand-year-old tradition of natural histories, Bacon tried to clarify their uses and limits. Perhaps in revulsion against the magical or superstitious element found in many of them, he declared that a good natural history should present fact shorn of explanation. A natural history of the world would enumerate all observable phenomena, category by category (for example, winds, heat and cold, plants, animals, and minerals). Only when savants had compiled this information could they ascertain the underlying causes of phenomena, that is, examine the natural philosophy of the world. Given the immensity of the first task, an ideal Baconian approach would make it difficult ever to reach the second stage.

Some natural histories, consistent with Bacon's recommendation, did little more than illustrate and describe flora and fauna without explaining their behavior or nature. Bauhin's Pinax, for example, the most comprehensive seventeenth-century guide to plants, described the external appearance, cultivation, and uses of each plant. Zoologists, tempted by analogies between human and animal behavior and impressed by the lessons of comparative anatomy, went further. In his ornithology, for example, Aldrovandi not only portrayed the skeletal structure and reproductive organs of birds but also discussed the development of the chick in the egg, the roles of male and female in reproduction, and the sexual mores of fowls. For Aldrovandi, knowing animals entailed knowing their anatomy and physiology and explaining their behavioral characteristics. Aldrovandi's and Bauhin's different methods show how the natural histories of plants and animals diverged at the beginning of the seventeenth century. Zoological research was prompted primarily by comparative anatomy,

while the principal incentive to study plants was pharmacological, so that books on plants tended to be practical manuals.

In the course of the century, however, several influences altered ideas about how to study plants. The conceptions of natural history and natural philosophy changed, bringing botanical and zoological research closer in intent and method. First, the number of known plants grew quickly, making new compendia necessary. Second, among the species discovered in the new world were sensitive plants (fig. 1), which challenged the old Aristotelian distinction between plants and animals, for they moved when touched. Third, aesthetic appreciation of plants and gardens as objects of beauty was developing, and with it a desire to collect botanical illustrations. Insofar as this change represented a taste for plants on their own merits — and not as symbols or simples — it also represented a new way of thinking about plants that would affect botanical studies. Fourth, by redefining the differences between humans and animals, mechanistic theories created a greater incentive to test assumptions about plants and animals — especially the view that plants and animals were analogous in many respects — by searching for the limits of their similarities. Fifth, savants tried to put their causal accounts of the universe on a new footing. Astronomers sought a new celestial mechanics and developed a mathematical key to the language of the universe, while students of terrestrial phenomena turned to chemical and mechanical explanation to account for animal and vegetable processes. Sixth, as new scientific fields emerged and the interdisciplinary character of scientific inquiry was placed on a firmer footing, traditional fields were redefined and theories or methods that developed in one area were applied to another.^[1]

All of these factors influenced botanical research, which emerged in the late seventeenth century as a more independent field of study. From the appearance of Bauhin's work until the 1660s, no major treatises on plants had appeared. But during the 1660s Robert Hooke included plants in his Micrographia, Johann Daniel Major suggested that sap circulated in plants like blood in animals, and Robert Morison and John Ray began a new assault on the problem of classification. By the 1670s Nehemiah Grew was publishing anatomical studies of roots and stems, and Marcello Malpighi took up these inquiries in the 1680s.

The Academy was thus founded at a time when botanical research was in flux, exhibiting at once conservative and innovative elements. The Academy's own projects reflect both tendencies. Academicians settled quickly on publishing a definitive natural history of plants, to be produced as a team effort. This study was old-fashioned and stressed descriptions,

Fig. 1.
Herba mimosa frutescens/Sensitive en arbrisseau.
(From Estampes; drawn and engraved by Chastillon;
photograph courtesy of Bibliothèque Nationale, Paris.)

lists of synonyms and sources, explanations of medical uses, tips on cultivation, and illustrations, all reminiscent of Bauhin. At the same time, however, academicians introduced new elements such as the chemical analysis of plants. The blend of old and new features, the research methods chosen, and the roles of the patrons and of the institution all contribute to the story of the Academy's natural history of plants. By and large, that story is one of failure. Academicians recorded hundreds of pages of botanical notes and compiled more than twenty volumes of notebooks from chemical experiments. They drafted assorted chapters, prepared more than three hundred engravings, and wrote several books. But they never published the natural history as planned.

The Academy's natural history of plants failed for four reasons: intellectual, natural, accidental, and institutional. The project was intellectually ambitious, its scope and style innovative but overly inclusive. Academicians never focused their inquiry adequately but studied plants rare and common, medicinal and edible, French and foreign. They disagreed about how to describe plants — where to start, what to emphasize, and how to balance bookishness and observation — and they were sometimes undecided whether a specimen corresponded with a plant already described in the literature. Natural obstacles, such as obtaining and cultivating uncommon plants, also taxed their ingenuity. Since they did not keep a herbarium of dried specimens, they could not always check their descriptions or illustrations. Such intellectual and natural problems were not peculiar, however, to academicians. Anyone writing a natural history of plants faced these difficulties, and academicians' solutions and mistakes resembled those of their contemporaries.

The Academy's project was distinctive in certain respects. It was to include chemical analyses of the plants. It was the work of an institution, not an individual. It suffered from editorial rivalry, uncertain funding, and theft. The patronage that made the project possible also undermined its completion. These special features of the project contributed to its failure. Academicians were able to isolate the most treacherous intellectual problem — chemical analysis — from the project, but they could not prevent the accidents and institutional problems that damaged their natural history. To understand how all these factors affected the project, it is necessary to know why the Academy decided to prepare a natural history of plants at all, how innovative the project was, what was the institutional character of members' efforts, and how patronage influenced their work.