Western Civilization - History Of European Society

The Culture of Old Regime Europe379

he translated as “Have the courage to use your own
reason!”
The Enlightenment developed from several
trends in European thought. Skepticism had been one
of the dominant themes of seventeenth-century phi-
losophy, chiefly associated with the French philoso-
pher René Descartes. In works such as the Discourse on
Method(1637), he had advocated universal doubt; that
is, the doubting of everything until it can be proven.

Pierre Bayle had even taken the dramatic step of ap-

plying skeptical philosophy to the Bible. Bayle, a

Frenchman whose advanced ideas forced him to live

in the greater freedom of Holland, proposed “a de-

tailed refutation of the unreasonable deference

given to tradition,” and he included Christianity

within that tradition. All religious questions,

including the reading of the Bible, “require the

use of reason.”

A second fundamental source of the Enlighten-

ment thought was the scientific revolution of the

seventeenth century, especially Sir Isaac Newton’s

synthesis of the accomplishments of many scientists.

Newton had built upon a scientific revolution that

had destroyed the geocentric theory of the universe,

instead placing the Sun at the center in a heliocen-

tric theory. This required sweeping, counterintuitive

adjustments in European thought. For the heliocen-

tric theory to be true, the Earth must move, at

tremendously high speeds, around the Sun and the

Sun did not rise or set, it merely appeared to do so

because the rotation of the Earth turned a viewer to-

ward or away from the Sun. Christian theologians

fought such conclusions. The Catholic Church

placed the writings of astronomers on the Index of

prohibited books, arguing that “it is the Holy Spirit’s

intention to teach us how to go to heaven, not how

the heavens go.”

The Enlightenment canonized Newton because

he convinced the intelligentsia that the new astron-

omy was correct and the churches were wrong. His

greatest fame resulted from stating the Principle of

Universal Gravitation (the law of gravity) in his mas-

terwork, Principia mathematica(1687). The “universal”

element of the law of gravity fascinated the

philosophes of the eighteenth century. Newton

proved to them that human reason could discover

“the universal qualities of all bodies whatsoever.”

Voltaire, who popularized Newton’s work in Elements

of the Philosophy of Newton(1738), proclaimed him “the

greatest and rarest genius that ever rose for the orna-

mentation and instruction of the species.” The Eng-

lish poet Alexander Pope was equally lavish in

praising the Newtonian synthesis in his Essay on Man

(1734): “Nature and nature’s law lay hid in night/God

said, ‘Let Newton be,’ and all was light.” And around

the Western world, philosophes placed a bust of

Newton in their study—as Thomas Jefferson did at

Monticello—as a reminder that human reason could

find universal natural laws.

A third source of Enlightenment thought, alongside

philosophic skepticism and scientific rationalism, was

DOCUMENT 20.1

Immanuel Kant: Enlightenment

Immanuel Kant (1724–1804) was a distinguished German

philosopher and a professor of logic and metaphysics at the

University of Königsberg in eastern Prussia. He was already

famous for his greatest work—The Critique of Pure Rea-

son ( 1781 )—when he published the essay “What Is Enlight-

enment?” (1784), from which the following excerpt is taken.

Enlightenment is man’s leaving his self-caused im-

maturity. Immaturity is the incapacity to use one’s

intelligence without the guidance of another. Such

immaturity is self-caused if it is not caused by lack

of intelligence, but by lack of determination and

courage to use one’s intelligence without being

guided by another. Sapere Aude!Have the courage

to use your own reason! is therefore the motto of

the enlightenment.

Through laziness and cowardice, a large part

of mankind, even after nature has freed them from

alien guidance, gladly remain immature. It is be-

cause of laziness and cowardice that it is so easy to

usurp the role of guardians. It is so comfortable to

be a minor! If I have a book which provides mean-

ing for me, a pastor who has conscience for me, a

doctor who will judge my diet for me, and so on,

then I do not need to exert myself. I do not have

any need to think; if I can pay, others will take

over the tedious job for me....

But it is more nearly possible for a public to

enlighten itself: this is even inescapable if only the

public is given its freedom.... All that is required

for this enlightenment is freedom;and particularly

the least harmful of all that may be called freedom,

namely the freedom for man to make public use of

his reason in all matters.

Kant, Immanuel. “What Is Enlightenment?” In Carl J. Friedrich,

ed., The Philosophy of Kant.New York: Modern Library, 1949.