Highly prolific, “his preserved works alone would fill about a dozen
volumes of approximately one thousand pages each.”^13 If Aristotle was
the first to perform animal dissection, and the first to postulate that the
organs of the body had individual function, it was Galen who raised
animal dissection and vivisection (dissecting on live animals) to another
level. The major revolution in anatomical learning had occurred in
Alexandria, led by Herophilus and Erasistratus, who were both
contemporaries of Epicurus, in the 3rd century B.C.E. Alexander the Great
had just founded his city at the time of their birth; it was a frontier city on
the Mediterranean near the mouth of the Nile, surrounded by barbarians. It
is possible that dissection (and even, shockingly, vivisection) was
performed on convicted criminals in that city. Steven Johnson has
described the “hummingbird effect, an innovation, or cluster of
innovations, in one field [that] ends up triggering changes that seem to
belong to a different domain altogether ... sometimes change comes about
through the actions of political leaders or inventors ...”^14 The young city
of Alexandria, as a Hellenistic outpost, was the ideal laboratory for the
Greek natural philosophers, with a tradition (handed down from
Alexander) of assimilating local customs and leaders and inculcating
international students. For almost one thousand years it was the greatest
city of learning in the world and had the largest library (of papyrus
scrolls). The marriage of ancient Egyptian scholarship, Greek
philosophical insight and empiricism, and contributions of conquered
Persian and Indian peoples made Alexandria the ideal city for Galen to
complete his studies.
Galen’s great work On Anatomical Procedures is a wonder. It was his
last major work, and was based on a lifetime of anatomical investigation.
It has been said that Galen, though not the founder of the science of
anatomy, was its first important witness, and this work is his pièce de
résistance. Like most anatomy books, there is an abundance of information
on bones, muscles, blood vessels, and organs. However, much of the
writing is imbued with Hippocratic humoral physiology; it is laughably
wrong when examined today, but it was the authoritative work until
Vesalius’s De humani corporis fabrica (On the Fabric of the Human Body)
was published in 1543. So highly regarded was Galen that Vesalius, as we
shall see, had to tiptoe around criticizing the master and gently sow the
first seeds of doubts about his authority.