Preindustrial Europe: Science, the Economy, and Political Reorganization 295ories of the Epicureans. To do so, he was forced to posit
the existence of a vacuum. The possibility of nothing-
ness had been denied by virtually everyone from Aris-
totle to Descartes, but the results of barometric
experiments by Toricelli and by Blaise Pascal (1623–62)
could be explained in no other way. In 1650 Otto von
Guericke ended the debate by constructing an air pump
with which a vacuum could be created. These efforts in
turn inspired Robert Boyle (1627–91) to formulate his
laws about the behavior of gases.
Interest in scientific inquiry was assuming the pro-
portions of a fad. All over Europe, men of leisure and
education were examining the physical world and de-
veloping theories about it. Many, including Boyle and
Pascal, were also gifted writers whose work inspired
others to emulate them. Science was becoming a move-
ment, and it was only a matter of time until that move-
ment was institutionalized. The English Royal Society
and the French Academie des Sciences were founded in
the 1660s, the latter under the patronage of Louis XIV’s
minister, Jean-Baptiste Colbert (1619–83). Colbert, like
England’s King Charles II, was quick to perceive the
possible connection between the new science and
improved technologies for war, agriculture, and manu-
facturing. Not all of the work performed was useful,
and much of it remained tied to the earlier vision of an
organic, providential universe, but mechanistic and
mathematical views gained ground steadily throughout
the century.
In physics, the movement culminated in the work
of Isaac Newton (1642–1727). A professor at Cam-
bridge and a member of the Royal Society, Newton was
in some respects an odd character who spent at least as
much time on alchemy and other occult speculations as
he did on mathematics and physics. In spite of this, he
formulated the laws of planetary motion and of gravity,
thereby completing the work begun by Kepler and
Galileo and establishing a cosmology that dominated
Western thought until the publication of Einstein’s the-
ories in 1904.
In his Principia,or Mathematical Principles of Natural
Philosophy,presented to the Royal Society in 1686,
Newton formulated three laws of motion: (1) Every ob-
ject remains either at rest or in motion along a straight
line until it is deflected or resisted by another force (the
law of inertia); (2) The rate of change in the motion of
an object is proportionate to the force acting upon it;
and (3) To every action there is an equal and opposite
reaction. These formulations accounted not only for
the behavior of moving objects on Earth, but also for
the continuing movement of the planets. He then per-
fected Kepler’s theories by demonstrating how the
planets move through a vacuum in elliptical orbits un-
der the influence of a force centered upon the Sun.
That force was gravity, which he defined as the attrac-
tive force between two objects (see document 16.2). It
is directly proportionate to the product of their masses
and inversely proportionate to the square of the dis-
tances between them. To many, these theories ex-
plained the mysteries of a universe that acted like
clockwork—smooth, mechanical, and eternal. Newton,
who was a deeply religious man, would not have been
pleased at the use to which his ideas would soon be put
by the philosophers of the eighteenth-century Enlight-
enment.DOCUMENT 16.1
Galileo: Scientific Proof
In this excerpt from The Assayer,Galileo attacks an oppo-
nent for arguing in the traditional manner by compiling lists
of authorities who support his position. It shows not only the
gulf that separated scientific thinking from that of the tradi-
tionalists, but also provides some indication of how Galileo
made enemies with his pen.Sarsi goes on to say that since this experiment of
Aristotle’s has failed to convince us, many other
great men have also written things of the same
sort. But it is news to me that any man would actu-
ally put the testimony of writers ahead of what ex-
perience shows him. To adduce more witnesses
serves no purposes, Sarsi, for we have never denied
that such things have been written and believed.
We did say they are false, but so far as authority is
concerned yours alone is as effective as an army’s
in rendering the events true or false. You take your
stand on the authority of many poets against our
experiments. I reply that if those poets could be
present at our experiments they would change
their views, and without disgrace they could say
they had been writing hyperbolically—or even ad-
mit they had been wrong....
I cannot but be astonished that Sarsi would
persist in trying to prove by means of witnesses
something that I may see for myself at any time by
means of experiment.
Galilei, Galileo. “The Assayer,” trans. Stillman Drake. In Still-
man Drake, Discoveries and Opinions of Galileo,pp. 270–271.
New York: Doubleday, 1957.