Many historians of science consider Rudolf Virchow the greatest of all pathologists. Virchow was best known as the leading pioneer in the field of cellular pathology. In medieval physiology it was thought that prominent bodily fluids, including blood, phlegm, choler, and bile determined the character and health of a person, and during the nineteenth century many scientists still relied on these humoral theories to explain diseases. Virchow's cell theory, the essence of which is brilliantly encapsulated in the axiom Omnis cellula e cellula, stating that every cell arises from a previously existing cell, virtually dismantled the humoral theories that had dominated the healing arts for more than twenty centuries, and laid the groundwork for a more rational and systematic mode of study.

Virchow was born on October 13, 1821, in Schivelbein, Pomerania, Prussia. He began his medical education in 1839 at the Friedrich Wilhelm Institute of the University of Berlin, where...