To the twentieth century tourist, the name Zwinger brings to mind the beautiful palace built in Dresden in 1709 by King Augustus the Strong of Saxony. In German, Zwinger means an open area between two surrounding walls built to defend a city. But none of these have anything to do with Theodor Zwinger. He was a Swiss physician born in Basel in 1533. After studying in his hometown, he went to Paris. By 1553 he was in Padua, attending the lectures of the great anatomist Fallopius, but also perfecting his knowledge of ancient Greek and translating the inscriptions found on ancient statues. In 1554, he received his medical doctorate.

Zwinger then went to practice medicine in Basel. He gained renown and served as personal doctor to two popes. He wrote on epidemiology and on the origins of diseases, published a multitude of medical treatises recording his observations and approaches to treatment, and described in detail the clinical features of influenza. Botany was one of his many interests, and in Basel, he maintained a botanical garden and cultivated medicinal plants.

Zwinger’s passion was compiling encyclopedic works. His most famous work was Theatrum Humanae Vitae, a massive compendium of knowledge published in 1565. It covered philosophy, mathematics, natural history, geography, medicine, and mythology, drawing heavily on classical and medieval sources as well as on the latest Renaissance scholarship. Organized thematically into over fifty books covering different fields of knowledge, it was carefully structured and cross-referenced to make it readable and navigable. Maps and illustrations were added to aid understanding.

In Theatrum Humanae Vitae, Zwinger attempted to bring together into one systematic work all key areas of human knowledge. Immensely popular, it went through many expanded editions during Zwinger’s lifetime. It was translated into German and English and was used by scholars across Europe as a reference work. It helped systematize many fields of knowledge and transmit the learning of antiquity and the Middle Ages to the Renaissance era. It influenced many later encyclopedias.

In addition to his main work, Zwinger also published books on travel, poetry, and philosophy. In Basel, Zwinger held successive chairs in Greek (1565), ethics (1571), and finally theoretical medicine (1580). His reputation reached across Europe and he corresponded with many learned intellectuals of his age. In recognition of his accomplishments, the University of Basel named an institute after him.