Development of botany and zoology

During the 12th century the growth of biology was sporadic. Nevertheless, it was during that time that botany was developed from the study of plants with healing properties; similarly, from veterinary medicine and the pleasures of the hunt came zoology. Because of the interest in medicinal plants, herbs in general began to be described and illustrated in a realistic manner. Although Arabic science was well developed during the period and was far in advance of Latin, Byzantine, and Chinese cultures, it began to show signs of decline. Latin learning, on the other hand, rapidly increasing, was best exemplified perhaps by the mid-13th-century German scholar Albertus Magnus (Saint Albert the Great), who was probably the greatest naturalist of the Middle Ages. His biological writings (De vegetabilibus, seven books, and De animalibus, 26 books) were based on the classical Greek authorities, predominantly Aristotle. But in spite of that classical basis, a significant amount of his work contained new observations and facts; for example, he described with great accuracy the leaf anatomy and venation of the plants he studied.

Albertus was particularly interested in plant propagation and reproduction and discussed in some detail the sexuality of plants and animals. Like his Greek predecessors, he believed in spontaneous generation; he also believed that animals were more perfect than plants, because they required two individuals for the sexual act. Perhaps one of Albertus’s greatest contributions to medieval biology was the denial of many superstitions believed by his contemporaries, a skepticism that, together with the reintroduction of Aristotelian biology, was to have profound effects on subsequent European science.

One of Albertus’s pupils was Thomas Aquinas, who, like his mentor, endeavoured to reconcile Aristotelian philosophy and the teachings of the church. Because Aquinas was a rationalist, he declared that God created the reasoning mind; hence, by true intellectual processes of reasoning, man could not arrive at a conclusion that was in opposition to Christian thought. Acceptance of this philosophy made possible a revival of rational learning that was consistent with Christian belief.