Natural History

Sources

Animals, Plants, and Minerals. An investigation of the medieval study of nature provides an interesting glimpse into how scientists of the period organized their knowledge and why they undertook their study. In some cases their investigations were academic, while in others they were seeking to elaborate and explain scripture, and in still others they had extremely practical goals. To document their studies they produced manuscript herbals, which illustrate plants and their medicinal properties; lapidaries, which show stones and their physical, magical, emblematic, or medicinal qualities; and bestiaries, which depict animals and describe their habits. In all these manuscripts mythical lore, Christian tradition, travelers’ tales, workmen’s knowledge of their crafts, and direct observations might mingle and intertwine to produce, in some cases, encyclopedic descriptions of the natural world.

Albertus Magnus. One of the most proficient and prolific medieval natural scientists was Albertus Magnus, a thirteenth-century Dominican administrator and teacher in west-central Germany. More than any other medieval scholar, Albertus was responsible for recovering and, most important, legitimizing Aristotle’s works on animals and plants, as well as works on those subjects by Arab writers. The teaching of Aristotle’s natural science had been condemned by the church in 1210, for these works by a pagan philosopher were considered dangerous, and hence wrong. (The existence of many scientific works by Arab scholars, who were non-Christians as well, also cast suspicion on the study of natural history.) Although the ban was lifted in 1234, most Christian scholars were not immediately favorable to Aristotle or the field of natural science. Albertus almost singlehandedly changed this attitude. Although today many of the natural phenomena that he reported seem odd or ludicrous, even when he claimed that he saw them himself, Albertus insisted that experience and theory must coincide, an idea that seems largely missing from the scientific writings of earlier authors. Among his many and impressive contributions to the physical sciences, his observations in botany, zoology, and geology are particularly notable. He compiled massive treatises listing hundreds, or in some cases thousands, of different plants, animals, or minerals. His remarkably complete descriptive passages are frequently complemented by his perceptive theoretical groupings or explications of causal relationships (as, for example, in the generation or evolution of plants and animals, the ecology of a region, or the uses of stones)—most derived from firsthand observations or reports from sources he trusted, not preconceived overarching theories. In particular, he rejected the ancient idea that fossils were created as they presently existed, accepting instead the idea of Arabic philosopher Avicenna (Ab? ’Al? al-Hussayn ibn ’Abd All?h ibn S?n?), who said they were petrified animals that had once been living.

Albertus’s Limitations. While Albertus’s works are masterful, the entries in them often seem fanciful to the modern reader. In many cases his descriptions confuse substances that are now known to be separate entities. Though the descriptive aspects of his works are similar to the entries found in modern guides to animals, plants, or minerals, Albertus’s writings are not simply descriptive. To the medieval natural scientist, description was only the first step in interpreting and determining the significance of an object. Entries for plants, animals, or rocks frequently start with where the substance is found and what authorities verify its existence or properties, but then they include information that surely cannot be verified by empirical observation. Like many people of his time, Albertus seems to have accepted that many stones have magical properties. Since institutions such as museums did not exist in the Middle Ages, and travel was difficult and severely limited, Albertus often relied on reports of faraway—and usually exotic—places. He took many things on faith from them, even when descriptions began with comments such as “It is said” or some other qualifying phrase. In many cases Albertus allowed the good reputation of the person who wrote the report to override com-monsense skepticism. Still, Albertus and other medieval writers on stones, plants, and animals made a valuable contribution to modern natural science by codifying information from antiquity and adding to from direct or indirect contemporary observations. They bequeathed to later ages a body of “facts” that form the foundation for the modern sciences of geology, botany, and zoology.

Sources

Albertus Magnus, The Book of Minerals, edited and translated by Dorothy Wyckoff (Oxford: Clarendon Press, 1967).

Albertus Magnus, On Animals, translated and annotated by Kenneth F. Kitchell Jr. and Irven Michael Resnick (Baltimore: Johns Hopkins University Press, 1999).

James A. Weisheipl, ed., Albertus Magnus and the Sciences: Commemorative Essays 1980 (Toronto: Pontifical Institute of Mediaeval Studies, 1980).