phy” of Agrippa von Nettesheim around 1515–1530 and the alchemical and
medical theories of Paracelsus in the 1530s. In common with the developments
in astronomy and in physiology, there was an explicit willingness to innovate
and to challenge received theories of the Greeks. But although Paracelsus and
other alchemists did some experimental work, there was nothing that could be
called a sustained development of discoveries nor heightened consensus.
I have already noted a fourth chain that I have called the mathematical
revolution. By the 1580s to the early 1600s, with the work of Galileo, this
flow of mathematical discovery making spilled over into experimental work in
physics. Around the same time, Stevin in Holland, who contributed to mathe-
matical calculation by introducing decimal fractions, developed mechanics and
hydrostatics. Stevin’s associate Snel worked on astronomy and refraction of
light (ca. 1618–1621); Snel’s protégé Beeckman conducted experiments (1626)
with pumps on hydrodynamics and combustion using equipment from his
father’s factory for candles and water conduits.^29
The four chains all use different methods: the mixture of math and obser-
vation in astronomy; dissection and eventually some experiment in physiology;
alchemical purifications in chemistry; the focus on simplifying calculations
which leads to the takeoff of mathematical discovery making, eventually spill-
ing over into giving mathematical descriptions of mechanical experiments in
physics. Is there a common impulse in these developments during the 1500s?
The most important social feature is that each chain gets its start when
particular fields of investigation become entwined with the core intellectual
networks. We have seen this already with the mathematicians from Cusanus
on through Galileo and Descartes. In astronomy, I have suggested that its
intellectual energy comes from its ability to attract the interest of theologians;
dangerous as it might be, the energy of controversy at the centers of attention
introduces innovative dynamics into specialized technical fields.
In physiology, the creative chain starts off with Servetus, a Spanish liberal
during the heady days of the early Reformation. Servetus deliberately moved
in the leading circles. From the court of the Emperor Charles V, he traveled to
Basel and Strasbourg to meet Erasmus, Bucer, and Schwenckfeld; at Paris he
met the young John Calvin—just then launching his own radical reforms—and
put forward his reform both of Galen and of the Trinity. Servetus is charac-
teristic of an era when cosmological-scientific speculation and theological
novelties could all be created together. There is the same mixture of scientific
occultism and theological reform among the “chemists”; Agrippa was a friend
of the English reformer Colet, while Paracelsus associated with Erasmus and
Franck as well as with Copernicus’s disciple Rheticus.
The impulse to innovate in scientific topics appears on the fringes of the
network of major intellectual controversy in the 1500s. Since the center of
560 • (^) Intellectual Communities: Western Paths