I
Opposition to the central ideas of the French Enlight-
enment, and of its allies and disciples in other European
countries, is as old as the movement itself. The procla-
mation of the autonomy of reason and the methods
of the natural sciences based on observation as the sole
reliable method of knowledge, and the consequent
rejection of the authority of revelation, sacred writings
and their accepted interpreters, tradition, prescription,
and every form of nonrational and transcendent sources
of knowledge, was naturally opposed by the churches
and religious thinkers of many persuasions. But such
opposition, largely because of the absence of common
ground between them and the philosophers of the
Enlightenment, made relatively little headway, save
by stimulating repressive steps against the spreading
of ideas regarded as dangerous to the authority of
Church or State. More formidable was the relativist
and skeptical tradition that went back to the ancient
world. The central doctrines of the progressive French
thinkers, whatever their disagreements among them-
selves, rested on the belief, rooted in the ancient doc-
trine of Natural Law, that human nature was funda-
mentally the same in all times and places; that local
and historical variations were unimportant compared
with the constant central core in terms of which human
beings could be defined as a species, like animals, or
plants, or minerals; that there were universal human
goals; that a logically connected structure of laws and
generalizations susceptible of demonstration and
verification could be constructed and replace the
chaotic amalgam of ignorance, mental laziness, guess-
work, superstition, prejudice, dogma, fantasy, and,
above all, the “interested error,” maintained by the
rulers of mankind and largely responsible for the
blunders, vices, and misfortunes of humanity.
It was further believed that the methods similar to
those of Newtonian physics which had achieved such
triumphs in the realm of inanimate nature could be
applied with equal success to the fields of ethics,
politics, and human relationships in general, in which
little progress had been made; with the corollary that
once this had been effected, it would sweep away
irrational and oppressive legal systems and economic
policies the replacement of which by the rule of rea-
son would rescue men from political and moral in-
justice and misery and set them on the path of wis-
dom, happiness, and virtue. Against this, there
persisted the doctrine that went back to the Greek
Sophists, Protagoras, Antiphon, and Critias, that
beliefs involving value-judgments, and the institutions
founded upon them, rested not on discoveries of objec-
tive and unalterable natural facts, but on human opin-
ion, which was variable and differed between different
societies and at different times; that moral and political
values, and in particular justice and social arrange-
ments in general rested on fluctuating human conven-
tion. This was summed up by the Sophist quoted by
Aristotle who declared that whereas fire burned both
here and in Persia, human institutions change under
our very eyes. It seemed to follow that no universal
truths established by scientific methods, that is, truths
that anyone could verify by the use of proper methods,
anywhere, at any time, could in principle be estab-
lished in human affairs.
This tradition reasserted itself strongly in the writ-
ings of such sixteenth-century skeptics as Cornelius
Agrippa, Montaigne, and Pierre Charron whose influ-
ence is discernible in the sentiments of thinkers and
poets in the Elizabethan and Jacobean age. Such skep-
ticism came to the aid of those who denied the claims
of the natural sciences or of other universal rational
schemas and advocated salvation in pure faith, like the
great Protestant reformers and their followers, and the
Jansenist wing of the Roman Church. The rationalist
belief in a single coherent body of logically deduced
conclusions, arrived at by universally valid principles
of thought and founded upon carefully sifted data of
observation or experiment, was further shaken by
sociologically minded thinkers from Bodin (1530-96)
to Montesquieu (1689-1755). These writers, using the
evidence of both history and the new literature of
travel and exploration in newly discovered lands, Asia
and the Americas, emphasized the variety of human
customs and especially the influence of dissimilar natu-
ral factors, particularly geographical ones, upon the
development of different human societies, leading to
differences of institutions and outlook, which in their
turn generated wide differences of belief and behavior.
This was powerfully reinforced by the revolutionary
doctrines of David Hume, especially by his demon-
stration that no logical links existed between truths of
fact, and such a priori truths as those of logic or mathe-
matics, which tended to weaken or dissolve the hopes
of those who, under the influence of Descartes and his
followers, thought that a single system of knowledge,
embracing all provinces and answering all questions,
could be established by unbreakable chains of logical
argument from universally valid axioms, not subject
to refutation or modification by any experience of an
empirical kind.
Nevertheless, no matter how deeply relativity about
human values or the interpretation of social, including
historical, facts entered the thought of social thinkers
of this type, they, too, retained a common core of
conviction that the ultimate ends of all men at all times
were, in effect, identical: all men sought the satisfaction
of basic physical and biological needs, such as food,
shelter, security, and also peace, happiness, justice, the
harmonious development of their natural faculties,
truth, and, somewhat more vaguely, virtue, moral per-
fection, and what the Romans had called humanitas.
Means might differ in cold and hot climates, moun-
tainous countries and flat plains, and no universal for-
mula could fit all cases without Procrustean results, but
the ultimate ends were fundamentally similar. Such
influential writers as Voltaire, D'Alembert, and Con-
dorcet believed that the development of the arts and
sciences were the most powerful human weapons in
attaining these ends, and the sharpest weapons in the
fight against ignorance, superstition, fanaticism,
oppression, and barbarism which crippled human effort
and frustrated men's search for truth and rational self-
direction. Rousseau and Mably believed, on the con-
trary, that the institutions of civilization were them-
selves a major factor in the corruption of men and their
alienation from nature, from simplicity, purity of heart
and the life of natural justice, social equality, and
spontaneous human feeling; artificial man had
imprisoned, enslaved, and ruined natural man. Never-
theless, despite profound differences of outlook, there
was a wide area of agreement about fundamental
points: the reality of Natural Law (no longer formu-
lated in the language of orthodox Catholic or Prot-
estant doctrine), of eternal principles by following
which alone men could become wise, happy, virtuous,
and free. One set of universal and unalterable princi-
ples governed the world for theists, deists, and atheists,
for optimists and pessimists, puritans, primitivists,
and believers in progress and the richest fruits of sci-
ence and culture; these laws governed inanimate and
animate nature, facts and events, means and ends,
private life and public, all societies, epochs, and civili-
zations; it was solely by departing from them that men
fell into crime, vice, misery. Thinkers might differ
about what these laws were, or how to discover them,
or who were qualified to expound them; that these laws
were real, and could be known, whether with certainty,
or only probability, remained the central dogma of the
entire Enlightenment. It was the attack upon this that
constitutes the most formidable reaction against this
dominant body of belief.