1 The Birth of Science - MSRI

124 5. Medicine and Other Empirical Sciences
vast that one is inclined to call it the birth of scientific medicine. This simultaneity
forcefully suggests two questions:
1. What features of Herophilus’ work make it appear so much more scientific
than pre-Hellenistic medicine? Put another way, is it the case, and
if so in what sense, that Herophilus’ anatomy, physiology and medicine
are sciences?
2. What is the relation between the (possible) birth of scientific medicine
and that of the exact sciences?
We start with some observations about the second question. Today, by
and large, the history of medicine enjoys few points of contact with the
history of the exact sciences and the history of technology (which themselves
interact but little with each other). At the same time, none of these
disciplines can by itself give an idea of the unity of third-century Hellenistic
culture, which has never been recovered since. It is easy to imagine
the interest with which Herophilus and his disciples followed advances
in exact science and technology. As we shall see, this interest is reflected
even in the choice of anatomical terms. Collaboration with other scientists
must have been fecund in both directions. It is likely, in particular, that the
physicians had dealings with Ctesibius. We know that the latter built a
water clock with a variable scale that compensated for the variable length
of the day, and we now see Herophilus using a timepiece of the same type
for a different purpose. We know that Ctesibius first introduced valves,
and we see Erasistratus and Herophilus describing heart valves. In the
pseudo-Galenic De historia philosopha we read:
Herophilus admits a motor capacity for bodies in the nerves, arteries,
and muscles. He accordingly thinks the lung has an additional page 165
tendency to dilate and contract. The natural activity of the lung, he
says, is, then, the drawing in of pneuma from the outside. . . 10
That the lungs draw something in because they expand may seem banal
today, but it probably first became clear around that time, in Alexandria,
and precisely because of the studies of Ctesibius. 11 Thus the descriptions
10 Pseudo-Galen, De historia philosopha, 103 = [von Staden: H], text 143c. For pneuma see page 68;
the meaning here may be simply “aspirated air” (cf. Heron’s definition of the term), particularly
in its physiological role, which would distinguish it from aer, air outside the body. Herophilus
maintains that pneuma, besides being breathed in, is also present in the arteries. The surviving
testimonia unfortunately say nothing about the passage of pneuma from lungs to arteries. It has
been said that Herophilus thought that arteries contained only pneuma and no blood, but a closer
analysis of the sources reveals that most likely he distinguished between the contents of veins
(blood alone) and that of the arteries (blood and pneuma). For discussion see [von Staden: H], pp.
264–267.
11 Heron also describes a medical device (syringe) based on suction due to expansion (Pneumatica,
II, xviii). It does not seem that the idea of suction depending on expansion was clear to Aristotle:
Revision: 1.9 Date: 2002/09/14 19:12:01