## 1. The True: Science, Epistemology and Metaphysics in the Enlightenment



In this era dedicated to human progress, the advancement of the
natural sciences is regarded as the main exemplification of, and fuel
for, such progress. Isaac Newton's epochal accomplishment in his
*Principia Mathematica* (1687), which, very briefly described,
consists in the comprehension of a diversity of physical phenomena
- in particular the motions of heavenly bodies, together with
the motions of sublunary bodies - in few relatively simple,
universally applicable, mathematical laws, was a great stimulus to the
intellectual activity of the eighteenth century and served as a model
and inspiration for the researches of a number of Enlightenment
thinkers. Newton's system strongly encourages the Enlightenment
conception of nature as an orderly domain governed by strict
mathematical-dynamical laws and the conception *of ourselves*
as capable of knowing those laws and of plumbing the secrets of nature
through the exercise of our unaided faculties. - The conception
of nature, and of how we know it, changes significantly with the rise
of modern science. It belongs centrally to the agenda of Enlightenment
philosophy to contribute to the new knowledge of nature, and to
provide a metaphysical framework within which to place and interpret
this new knowledge.


### 1.1 Rationalism and the Enlightenment



Rene Descartes' rationalist system of philosophy is one
of the pillars on which Enlightenment thought rests. Descartes
(1596-1650) undertakes to establish the sciences upon a secure
metaphysical foundation. The famous method of doubt Descartes employs
for this purpose exemplifies (in part through exaggerating) an
attitude characteristic of the Enlightenment. According to Descartes,
the investigator in foundational philosophical research ought to doubt
all propositions that can be doubted. The investigator determines
whether a proposition is dubitable by attempting to construct a
possible scenario under which it is false. In the domain of
fundamental scientific (philosophical) research, no other authority
but one's own conviction is to be trusted, and not one's
own conviction either, until it is subjected to rigorous skeptical
questioning. With his method, Descartes casts doubt upon the senses as
authoritative source of knowledge. He finds that God and the
immaterial soul are both better known, on the basis of innate ideas,
than objects of the senses. Through his famous doctrine of the dualism
of mind and body, that mind and body are two distinct substances, each
with its own essence, the material world (allegedly) known through the
senses becomes denominated as an "external" world, insofar
as it is external to the ideas with which one immediately communes in
one's consciousness. Descartes' investigation thus
establishes one of the central epistemological problems, not only of
the Enlightenment, but also of modernity: the problem of objectivity
in our empirical knowledge. If our evidence for the truth of
propositions about extra-mental material reality is always restricted
to mental content, content before the mind, how can we ever be certain
that the extra-mental reality is not other than we represent it as
being? Descartes' solution depends on our having secured prior
and certain knowledge of God. In fact, Descartes argues that
*all* human knowledge (not only knowledge of the material world
through the senses) depends on metaphysical knowledge of God.



Despite Descartes' grounding of all scientific knowledge in
metaphysical knowledge of God, his system contributes significantly to
the advance of natural science in the period. He attacks the
long-standing assumptions of the scholastic-aristotelians whose
intellectual dominance stood in the way of the development of the new
science; he developed a conception of matter that enabled mechanical
explanation of physical phenomena; and he developed some of the
fundamental mathematical resources - in particular, a way to
employ algebraic equations to solve geometrical problems - that
enabled the physical domain to be explained with precise, simple
mathematical formulae. Furthermore, his grounding of physics, and all
knowledge, in a relatively simple and elegant rationalist metaphysics
provides a model of a rigorous and complete secular system of
knowledge. Though major Enlightenment thinkers (for example Voltaire
in his *Letters on the English Nation*, 1734) embrace
Newton's physical system in preference to Descartes',
Newton's system itself depends on Descartes' earlier work,
a dependence to which Newton himself attests.



Cartesian philosophy also ignites various controversies in the latter
decades of the seventeenth century that provide the context of
intellectual tumult out of which the Enlightenment springs. Among
these controversies are the following: Are mind and body really two
distinct sorts of substances, and if so, what is the nature of each,
and how are they related to each other, both in the human being (which
presumably "has" both a mind and a body) and in a unified
world system? If matter is inert (as Descartes claims), what can be
the source of motion and the nature of causality in the physical
world? And of course the various epistemological problems: the problem
of objectivity, the role of God in securing our knowledge, the
doctrine of innate ideas, and others.



Baruch Spinoza's systematic rationalist metaphysics, which he
develops in his *Ethics* (1677) in part in response to problems
in the Cartesian system, is also an important basis for Enlightenment
thought. Spinoza develops, in contrast to Cartesian dualism, an
ontological monism according to which there is only one substance, God
or nature, with two attributes, corresponding to mind and body.
Spinoza's denial, on the basis of strict philosophical
reasoning, of the existence of a transcendent supreme being, his
identification of God with nature, gives strong impetus to the strands
of atheism and naturalism that thread through Enlightenment
philosophy. Spinoza's rationalist principles also lead him to
assert a strict determinism and to deny any role to final causes or
teleology in explanation. (See Israel 2001.)



The rationalist metaphysics of Leibniz (1646-1716) is also
foundational for the Enlightenment, particularly the German
Enlightenment (*die Aufklarung*), one prominent expression
of which is the Leibnizian rationalist system of Christian Wolff
(1679-1754). Leibniz articulates, and places at the head of
metaphysics, the great rationalist principle, the principle of
sufficient reason, which states that everything that exists has a
sufficient reason for its existence. This principle exemplifies the
characteristic conviction of the Enlightenment that the universe is
thoroughly rationally intelligible. The question arises of how this
principle itself can be known or grounded. Wolff attempts to derive it
from the logical principle of non-contradiction (in his *First
Philosophy or Ontology*, 1730). Criticism of this alleged
derivation gives rise to the general question of how formal principles
of logic can possibly serve to ground substantive knowledge of
reality. Whereas Leibniz exerts his influence through scattered
writings on various topics, some of which elaborate plans for a
systematic metaphysics which are never executed by Leibniz himself,
Wolff exerts his influence on the German Enlightenment through his
development of a rationalist system of knowledge in which he attempts
to demonstrate all the propositions of science from first principles,
known a priori.



Wolff's rationalist metaphysics is characteristic of the
Enlightenment by virtue of the *pretensions* of human reason
within it, not by reason's success in establishing its claims.
Much the same could be said of the great rationalist philosophers of
the seventeenth century. Through their articulation of the
*ideal* of scientia, of a complete science of reality, composed
of propositions derived demonstratively from a priori first
principles, these philosophers exert great influence on the
Enlightenment. But they fail, rather spectacularly, to realize this
ideal. To the contrary, what they bequeath to the eighteenth century
is metaphysics, in the words of Kant, as "a battlefield of
endless controversies." However, the controversies themselves
- regarding the nature of God, mind, matter, substance, cause,
et cetera, and the relations of each of these to the others -
provide tremendous fuel to Enlightenment thought.


### 1.2 Empiricism and the Enlightenment



Despite the confidence in and enthusiasm for human reason in the
Enlightenment - it is sometimes called "the Age of
Reason" - the rise of empiricism, both in the practice of
science and in the theory of knowledge, is characteristic of the
period. The enthusiasm for reason in the Enlightenment is primarily
not for the faculty of reason as an independent source of knowledge,
which is embattled in the period, but rather for the human cognitive
faculties generally; the Age of Reason contrasts with an age of
religious faith, not with an age of sense experience. Though the great
seventeenth century rationalist metaphysical systems of Descartes,
Spinoza and Leibniz exert tremendous influence on philosophy in the
Enlightenment; moreover, and though the eighteenth-century
Enlightenment has a rationalist strain (perhaps best exemplified by
the system of Christian Wolff), nevertheless, that the
*Encyclopedia* of Diderot and D'Alembert is dedicated to
three empiricists (Francis Bacon, John Locke and Isaac Newton),
signals the ascendency of empiricism in the period.



If the founder of the rationalist strain of the Enlightenment is
Descartes, then the founder of the empiricist strain is Francis Bacon
(1561-1626). Though Bacon's work belongs to the
Renaissance, the revolution he undertook to effect in the sciences
inspires and influences Enlightenment thinkers. The Enlightenment, as
the age in which experimental natural science matures and comes into
its own, admires Bacon as "the father of experimental
philosophy." Bacon's revolution (enacted in, among other
works, *The New Organon*, 1620) involves conceiving the new
science as (1) founded on empirical observation and experimentation;
(2) arrived at through the method of induction; and (3) as ultimately
aiming at, and as confirmed by, enhanced practical capacities (hence
the Baconian motto, "knowledge is power").



Of these elements of Bacon's revolution, the point about method
deserves special emphasis. Isaac Newton's work, which stands as
the great exemplar of the accomplishments of natural science for the
eighteenth century, is, like Bacon's, based on the inductive
method. Whereas rationalist of the seventeenth century tend to
conceive of scientific knowledge of nature as consisting in a system
in which statements expressing the observable phenomena of nature are
*deduced* from first principles, known a priori, Newton's
method begins with the observed phenomena of nature and reduces its
multiplicity to unity by induction, that is, by finding mathematical
laws or principles from which the observed phenomena can be derived or
explained. The evident success of Newton's
"bottom-up" procedure contrasts sharply with the seemingly
endless and fruitless conflicts among philosophers regarding the
meaning and validity of first principles of reason, and this contrast
naturally favors the rise of the Newtonian (or Baconian) method of
acquiring knowledge of nature in the eighteenth century.



The tendency of natural science toward progressive independence from
metaphysics in the eighteenth century is correlated with this point
about method. The rise of modern science in the sixteenth and
seventeenth centuries proceeds through its separation from the
presuppositions, doctrines and methodology of theology; natural
science in the eighteenth century proceeds to separate itself from
metaphysics as well. Newton proves the capacity of natural science to
succeed independently of a priori, clear and certain first principles.
The characteristic Enlightenment suspicion of all allegedly
authoritative claims the validity of which is obscure, which is
directed first of all against religious dogmas, extends to the claims
of metaphysics as well. While there are significant Enlightenment
thinkers who are metaphysicians - again, one thinks of Christian
Wolff - the general thrust of Enlightenment thought is
anti-metaphysical.



John Locke's *Essay Concerning Human Understanding*
(1690) is another foundational text of the Enlightenment. A main
source of its influence is the epistemological rigor that it displays,
which is at least implicitly anti-metaphysical. Locke undertakes in
this work to examine the human understanding in order to determine the
limits of human knowledge; he thereby institutes a prominent pattern
of Enlightenment epistemology. Locke finds the source of all our
ideas, the ideas out of which human knowledge is constructed, in the
senses and argues influentially against the rationalists'
doctrine of innate ideas. Locke's sensationalism exerts great
influence in the French Enlightenment, primarily through being taken
up and radicalized by the *philosophe*, Abbe de
Condillac. In the *Treatise on Sensations* (1754), Condillac
attempts to explain how all human knowledge arises out of sense
experience. Locke's epistemology, as developed by Condillac and
others, contributes greatly to the emerging science of psychology in
the period.



Locke and Descartes both pursue a method in epistemology that brings
with it the epistemological problem of objectivity. Both examine our
knowledge by way of examining the ideas we encounter directly in our
consciousness. This method comes to be called "the way of
ideas". Though neither for Locke nor for Descartes do
*all* of our ideas represent their objects by way of
*resembling* them (e.g., our idea of God does not represent God
by virtue of resembling God), our alleged knowledge of our environment
through the senses does depend largely on ideas that allegedly
resemble external material objects. The way of ideas implies the
epistemological problem of how we can know that these ideas do in fact
resemble their objects. How can we be sure that these objects do not
appear one way before the mind and exist in another way (or not at
all) in reality outside the mind? George Berkeley, an empiricist
philosopher influenced by John Locke, avoids the problem by asserting
the metaphysics of idealism: the (apparently material) objects of
perception are nothing but ideas before the mind. However,
Berkeley's idealism is less influential in, and characteristic
of, the Enlightenment, than the opposing positions of materialism and
Cartesian dualism. Thomas Reid, a prominent member of the Scottish
Enlightenment, attacks the way of ideas and argues that the immediate
objects of our (sense) perception are the common (material) objects in
our environment, not ideas in our mind. Reid mounts his defense of
naive realism as a defense of common sense over against the
doctrines of the philosophers. The defense of common sense, and the
related idea that the results of philosophy ought to be of use to
common people, are characteristic ideas of the Enlightenment,
particularly pronounced in the Scottish Enlightenment.


### 1.3 Skepticism in the Enlightenment



Skepticism enjoys a remarkably strong place in Enlightenment
philosophy, given that confidence in our intellectual capacities to
achieve systematic knowledge of nature is a leading characteristic of
the age. This oddity is at least softened by the point that much
skepticism in the Enlightenment is merely methodological, a tool meant
to serve science, rather than a position embraced on its own account.
The instrumental role for skepticism is exemplified prominently in
Descartes' *Meditations on First Philosophy* (1641), in
which Descartes employs radical skeptical doubt to attack prejudices
derived from learning and from sense experience and to search out
principles known with certainty which may serve as a secure foundation
for a new system of knowledge. Given the negative, critical,
suspicious attitude of the Enlightenment towards doctrines
traditionally regarded as well founded, it is not surprising that
Enlightenment thinkers employ skeptical tropes (drawn from the ancient
skeptical tradition) to attack traditional dogmas in science,
metaphysics and religion.



However, skepticism is not merely a methodological tool in the hands
of Enlightenment thinkers. The skeptical cast of mind is one prominent
manifestation of the Enlightenment spirit. The influence of Pierre
Bayle, another founding figure of the Enlightenment, testifies to
this. Bayle was a French Protestant, who, like many European
philosophers of his time, was forced to live and work in politically
liberal and tolerant Holland in order to avoid censorship and prison.
Bayle's *Historical and Critical Dictionary* (1697), a
strange and wonderful book, exerts great influence on the age. The
form of the book is intimidating: a biographical dictionary, with long
scholarly entries on obscure figures in the history of culture,
interrupted by long scholarly footnotes, which are in turn interrupted
by further footnotes. Rarely has a work with such intimidating
scholarly pretentions exerted such radical and liberating influence in
the culture. It exerts this influence through its skeptical
questioning of religious, metaphysical, and scientific dogmas.
Bayle's eclecticism and his tendency to follow arguments without
pre-arranging their conclusions make it difficult to categorize his
thought. It is the attitude of inquiry that Bayle displays, rather
than any doctrine he espouses, that mark his as distinctively
Enlightenment thought. He is fearless and presumptuous in questioning
all manner of dogma. His attitude of inquiry resembles both that of
Descartes' meditator and that of the person undergoing
enlightenment as Kant defines it, the attitude of coming to think for
oneself, of daring to know. This epistemological attitude, as manifest
in distrust of authority and reliance on one's own capacity to
judge, expresses the Enlightenment values of individualism and
self-determination.



This skeptical/critical attitude underlies a significant tension in
the age. While it is common to conceive of the Enlightenment as
supplanting the authority of tradition and religious dogma with the
authority of reason, in fact the Enlightenment is characterized by a
crisis of authority regarding any belief. This is perhaps best
illustrated with reference to David Hume's skepticism, as
developed in Book One of *A* *Treatise of Human Nature*
(1739-40) and in his later *Enquiries Concerning Human
Understanding* (1748). While one might take Hume's
skepticism to imply that he is an outlier with respect to the
Enlightenment, it is more convincing to see Hume's skepticism as
a flowering of a crisis regarding authority in belief that is internal
to the Enlightenment. Hume articulates a variety of skepticisms. His
"skepticism with regard to the senses" is structured by
the epistemological problem bound up with the way of ideas, described
above. Hume also articulates skepticism with regard to reason in an
argument that is anticipated by Bayle. Hume begins this argument by
noting that, though rules or principles in demonstrative sciences are
certain or infallible, given the fallibility of our faculties, our
applications of such rules or principles in demonstrative inferences
yield conclusions that cannot be regarded as certain or infallible. On
reflection, our conviction in the conclusions of demonstrative
reasoning must be qualified by an assessment of the likelihood that we
made a mistake in our reasoning. Thus, Hume writes, "all
knowledge degenerates into probability" (*Treatise*,
I.iv.i). Hume argues further that, given this degeneration, for any
judgment, our assessment of the likelihood that we made a mistake, and
the corresponding diminution of certainty in the conclusion, is
another judgment about which we ought make a further assessment, which
leads to a further diminution of certainty in our original conclusion,
leading "at last [to] a total extinction of belief and
evidence". Hume also famously questions the justification of
inductive reasoning and causal reasoning. According to Hume's
argument, since in causal reasoning we take our past observations to
serve as evidence for judgments regarding what will happen in
relevantly similar circumstances in the future, causal reasoning
depends on the assumption that the future course of nature will
resemble the past; and there is no non-circular justification of this
essential assumption. Hume concludes that we have no rational
justification for our causal or inductive judgments. Hume's
skeptical arguments regarding causal reasoning are more radical than
his skeptical questioning of reason as such, insofar as they call into
question even *experience itself* as a ground for knowledge and
implicitly challenge the credentials of Newtonian science itself, the
very pride of the Enlightenment. The question implicitly raised by
Hume's powerful skeptical arguments is whether *any*
epistemological authority at all can withstand critical scrutiny. The
Enlightenment begins by unleashing skepticism in attacking limited,
circumscribed targets, but once the skeptical genie is out of the
bottle, it becomes difficult to maintain conviction in any authority.
Thus, the despairing attitude that Hume famously expresses in the
conclusion to Book One of the *Treatise*, as the consequence of
his epistemological inquiry, while it clashes with the self-confident
and optimistic attitude we associate with the Enlightenment, in fact
reflects an essential possibility in a distinctive Enlightenment
problematic regarding authority in belief.


### 1.4 Science of Man and Subjectivism in the Enlightenment



Though Hume finds himself struggling with skepticism in the conclusion
of Book One of the *Treatise*, the project of the work as he
outlines it is not to advance a skeptical viewpoint, but to establish
a science of the mind. Hume is one of many Enlightenment thinkers who
aspire to be the "Newton of the mind"; he aspires to
establish the basic laws that govern the elements of the human mind in
its operations. Alexander Pope's famous couplet in *An Essay
on Man* (1733) ("Know then thyself, presume not God to scan/
The proper study of mankind is man") expresses well the intense
interest humanity gains in itself within the context of the
Enlightenment, as a partial substitute for its traditional interest in
God and the transcendent domain. Just as the sun replaces the earth as
the center of our cosmos in Copernicus' cosmological system, so
humanity itself replaces God at the center of humanity's
consciousness in the Enlightenment. Given the Enlightenment's
passion for science, the self-directed attention naturally takes the
form of the rise of the scientific study of humanity in the
period.



The enthusiasm for the scientific study of humanity in the period
incorporates a tension or paradox concerning the place of humanity in
the cosmos, as the cosmos is re-conceived in the context of
Enlightenment philosophy and science. Newton's success early in
the Enlightenment of subsuming the phenomena of nature under universal
laws of motion, expressed in simple mathematical formulae, encourages
the conception of nature as a very complicated machine, whose parts
are material and whose motions and properties are fully accounted for
by deterministic causal laws. But if our conception of nature is of an
exclusively material domain governed by deterministic, mechanical
laws, and if we at the same time deny the place of the supernatural in
the cosmos, then how does humanity itself fit into the cosmos? On the
one hand, the achievements of the natural sciences in general are the
great pride of the Enlightenment, manifesting the excellence of
distinctively human capacities. The pride and self-assertiveness of
humanity in the Enlightenment expresses itself, among other ways, in
humanity's making the study of itself its central concern. On
the other hand, the study of humanity in the Enlightenment typically
yields a portrait of us that is the opposite of flattering or
elevating. Instead of being represented as occupying a privileged
place in nature, as made in the image of God, humanity is represented
typically in the Enlightenment as a fully natural creature, devoid of
free will, of an immortal soul, and of a non-natural faculty of
intelligence or reason. The very title of J.O. de La Mettrie's
*Man a Machine* (1748), for example, seems designed to deflate
humanity's self-conception, and in this respect it is
characteristic of the Enlightenment "science of man". It
is true of a number of works of the Enlightenment, perhaps especially
works in the more radical French Enlightenment - notable here
are Helvetius's *Of the Spirit* (1758) and Baron
d'Holbach's *System of Nature* (1770) - that
they at once express the remarkable self-assertiveness of humanity
characteristic of the Enlightenment in their scientific aspirations
while at the same time painting a portrait of humanity that
dramatically deflates its traditional self-image as occupying a
privileged position in nature.



The methodology of epistemology in the period reflects a similar
tension. Given the epistemological role of Descartes' famous
"*cogito, ergo sum*" in his system of knowledge,
one might see Descartes' epistemology as already marking the
transition from an epistemology privileging knowledge of God to one
that privileges self-knowledge instead. However, in Descartes'
epistemology, it remains true that knowledge of God serves as the
necessary foundation for all human knowledge. Hume's
*Treatise* displays such a re-orientation less ambiguously. As
noted, Hume means his work to comprise a science of the mind or of
man. In the Introduction, Hume describes the science of man as
effectively a foundation for all the sciences since all sciences
"lie under the cognizance of men, and are judged of by their
powers and faculties." In other words, since all science is
human knowledge, scientific knowledge *of humanity* is the
foundation of the sciences. Hume's placing the science of man at
the foundation of all the sciences both exemplifies the privilege
afforded to "mankind's study of man" within the
Enlightenment and provides an interpretation of it. But Hume's
methodological privileging of humanity in the system of sciences
contrasts sharply with what he says in the body of his science about
humanity. In Hume's science of man, reason as a faculty of
knowledge is skeptically attacked and marginalized; reason is
attributed to other animals as well; belief is shown to be grounded in
custom and habit; and free will is denied. So, even as knowledge of
humanity supplants knowledge of God as the keystone of the system of
knowledge, the scientific perspective on humanity starkly challenges
humankind's self-conception as occupying a privileged position
in the order of nature.



Immanuel Kant explicitly enacts a revolution in epistemology modeled
on the Copernican in astronomy. As characteristic of Enlightenment
epistemology, Kant, in his *Critique of Pure Reason* (1781,
second edition 1787) undertakes both to determine the limits of our
knowledge, and at the same time to provide a foundation of scientific
knowledge of nature, and he attempts to do this by examining our human
faculties of knowledge critically. Even as he draws strict limits to
rational knowledge, he attempts to defend reason as a faculty of
knowledge, as playing a necessary role in natural science, in the face
of skeptical challenges that reason faces in the period. According to
Kant, scientific knowledge of nature is not merely knowledge of what
*in fact* happens in nature, but knowledge of the causal laws
of nature according to which what in fact happens *must*
happen. But how is knowledge of necessary causal connection in nature
possible? Hume's investigation of the idea of cause had made
clear that we cannot know causal necessity through experience;
experience teaches us at most what in fact happens, not what
*must* happen. In addition, Kant's own earlier critique
of principles of rationalism had convinced him that the principles of
("general") logic also cannot justify knowledge of
*real* necessary connections (in nature); the formal principle
of non-contradiction can ground at best the deduction of one
*proposition* from another, but not the claim that one
*property* or *event* must follow from another in the
course of nature. The generalized epistemological problem Kant
addresses in the *Critique of Pure Reason* is: how is science
possible (including natural science, mathematics, metaphysics), given
that all such knowledge must be (or include) knowledge of real,
substantive (not merely logical or formal) necessities. Put in the
terms Kant defines, the problem is: how is synthetic, a priori
knowledge possible?



According to Kant's Copernican Revolution in epistemology
addressed to this problem, objects must conform themselves to human
knowledge rather than knowledge to objects. Certain cognitive forms
lie ready in the human mind - prominent examples are the pure
concepts of substance and cause and the forms of intuition, space and
time; given sensible representations must conform themselves to these
forms in order for human experience (as empirical knowledge of nature)
to be possible at all. We can acquire scientific knowledge of nature
because we constitute it a priori according to certain cognitive
forms; for example, we can know nature as a causally ordered domain
because we originally synthesize a priori the given manifold of
sensibility according to the category of causality, which has its
source in the human mind.



Kant saves rational knowledge of nature by limiting rational knowledge
to nature. According to Kant's argument, we can have rational
knowledge only of the domain of possible experience, not of
supersensible objects such as God and the soul. Moreover Kant's
solution brings with it a kind of idealism: given the mind's
role in constituting objects of experience, we know objects only as
*appearances*, only as they appear according to our faculties,
not as they are in themselves. This is the subjectivism of
Kant's epistemology. Kant's epistemology exemplifies
Enlightenment thought by replacing the theocentric conception of
knowledge of the rationalist tradition with an anthropocentric
conception.



However, Kant means his system to make room for humanity's
practical and religious aspirations toward the transcendent as well.
According to Kant's idealism, the realm of nature is limited to
a realm of appearances, and we can intelligibly think supersensible
objects such as God, freedom and the soul, though we cannot know them.
Through the postulation of a realm of unknowable noumena (things in
themselves) over against the realm of nature as a realm of
appearances, Kant manages to make place for practical concepts that
are central to our understanding of ourselves even while grounding our
scientific knowledge of nature as a domain governed by deterministic
causal laws. Though Kant's idealism is highly controversial from
its initial publication, a main point in its favor, according to Kant
himself, is that it reconciles, in a single coherent tension, the main
tension between the Enlightenment's conception of nature, as
ordered according to deterministic causal laws, and the
Enlightenment's conception of ourselves, as morally free, as
having dignity, and as perfectible.


### 1.5 Emerging Sciences and the *Encyclopedia*



The commitment to careful observation and description of phenomena as
the starting point of science, and then the success at explaining and
accounting for observed phenomena through the method of induction,
naturally leads to the development of new sciences for new domains in
the Enlightenment. Many of the human and social sciences have their
origins in the eighteenth century (e.g., history, anthropology,
aesthetics, psychology, economics, even sociology), though most are
only formally established as autonomous disciplines later. The
emergence of new sciences is aided by the development of new
scientific tools, such as models for probabilistic reasoning, a kind
of reasoning that gains new respect and application in the period.
Despite the multiplication of sciences in the period, the ideal
remains to comprehend the diversity of our scientific knowledge as a
unified system of science; however, this ideal of unity is generally
taken as regulative, as an ideal to emerge in the ever-receding
end-state of science, rather than as enforced from the beginning by
regimenting science under a priori principles.



As exemplifying these and other tendencies of the Enlightenment, one
work deserves special mention: the *Encyclopedia*, edited by
Denis Diderot and Jean La Rond d'Alembert. The
*Encyclopedia* (subtitled: "*systematic dictionary of
the sciences, arts and crafts*") was published in 28 volumes
(17 of text, 11 of plates) over 21 years (1751-1772), and
consists of over 70,000 articles, contributed by over 140
contributors, among them many of the luminaries of the French
Enlightenment. The work aims to provide a compendium of existing human
knowledge to be transmitted to subsequent generations, a transmission
intended to contribute to the progress and dissemination of human
knowledge and to a positive transformation of human society. The
orientation of the *Encyclopedia* is decidedly secular and
implicitly anti-authoritarian. Accordingly, the French state of the
*ancien regime* censors the project, and it is completed
only through the persistence of Diderot. The collaborative nature of
the project, especially in the context of state opposition,
contributes significantly to the formation of a shared sense of
purpose among the wide variety of intellectuals who belong to the
French Enlightenment. The knowledge contained in the
*Encyclopedia* is self-consciously social both in its
production - insofar as it is immediately the product of what
the title page calls "a society of men of letters" -
and in its address - insofar as it is primarily meant as an
instrument for the education and improvement of society. It is a
striking feature of the *Encyclopedia*, and one by virtue of
which it exemplifies the Baconian conception of science characteristic
of the period, that its entries cover the whole range and scope of
knowledge, from the most abstract theoretical to the most practical,
mechanical and technical. 


## 2. The Good: Political Theory, Ethical Theory and Religion in the Enlightenment


### 2.1 Political Theory



The Enlightenment is most identified with its political
accomplishments. The era is marked by three political revolutions,
which together lay the basis for modern, republican, constitutional
democracies: The English Revolution (1688), the American Revolution
(1775-83), and the French Revolution (1789-99). The
success at explaining and understanding the natural world encourages
the Enlightenment project of re-making the social/political world, in
accord with the models we allegedly find in our reason. Enlightenment
philosophers find that the existing social and political orders do not
withstand critical scrutiny. Existing political and social authority
is shrouded in religious myth and mystery and founded on obscure
traditions. The criticism of existing institutions is supplemented
with the positive work of constructing in theory the model of
institutions as they ought to be. We owe to this period the basic
model of government founded upon the consent of the governed; the
articulation of the political ideals of freedom and equality and the
theory of their institutional realization; the articulation of a list
of basic individual human rights to be respected and realized by any
legitimate political system; the articulation and promotion of
toleration of religious diversity as a virtue to be respected in a
well ordered society; the conception of the basic political powers as
organized in a system of checks and balances; and other now-familiar
features of western democracies. However, for all the enduring
accomplishments of Enlightenment political philosophy, it is not clear
that human reason proves powerful enough to put a concrete, positive
authoritative ideal in place of the objects of its criticism. As in
the epistemological domain, reason shows its power more convincingly
in criticizing authorities than in establishing them. Here too the
question of the limits of reason is one of the main philosophical
legacies of the period. These limits are arguably vividly illustrated
by the course of the French Revolution. The explicit ideals of the
French Revolution are the Enlightenment ideals of individual freedom
and equality; but, as the revolutionaries attempt to devise rational,
secular institutions to put in place of those they have violently
overthrown, eventually they have recourse to violence and terror in
order to control and govern the people. The devolution of the French
Revolution into the Reign of Terror is perceived by many as proving
the emptiness and hypocrisy of Enlightenment reason, and is one of the
main factors which account for the end of the Enlightenment as an
historical period.



The political revolutions of the Enlightenment, especially the French
and the American, were informed and guided to a significant extent by
prior political philosophy in the period. Though Thomas Hobbes, in his
*Leviathan* (1651), defends the absolute power of the political
sovereign, and is to that extent opposed to the revolutionaries and
reformers in England, this work is a founding work of Enlightenment
political theory. Hobbes' work originates the modern social
contract theory, which incorporates Enlightenment conceptions of the
relation of the individual to the state. According to the general
social contract model, political authority is grounded in an agreement
(often understood as ideal, rather than real) among individuals, each
of whom aims in this agreement to advance his rational self-interest
by establishing a common political authority over all. Thus, according
to the general contract model (though this is more clear in later
contract theorists such as Locke and Rousseau than in Hobbes himself),
political authority is grounded not in conquest, natural or divinely
instituted hierarchy, or in obscure myths and traditions, but rather
in the rational consent of the governed. In initiating this model,
Hobbes takes a naturalistic, scientific approach to the question of
how political society ought to be organized (against the background of
a clear-eyed, unsentimental conception of human nature), and thus
decisively influences the Enlightenment process of secularization and
rationalization in political and social philosophy.



Baruch Spinoza also greatly contributes to the development of
Enlightenment political philosophy in its early years. The
metaphysical doctrines of the *Ethics* (1677) lay the
groundwork for his influence on the age. Spinoza's arguments
against Cartesian dualism and in favor of substance monism, the claim
in particular that there can only be one substance, God or nature, was
taken to have radical implications in the domains of politics, ethics
and religion throughout the period. Spinoza's employment of
philosophical reason leads to the denial of the existence of a
transcendent, creator, providential, law-giving God; this establishes
the opposition between the teachings of philosophy, on the one hand,
and the traditional orienting practical beliefs (moral, religious,
political) of the people, on the other hand, an opposition that is one
important aspect of the culture of the Enlightenment. In his main
political work, *Tractatus Theologico-Politicus* (1677),
Spinoza, building on his rationalist naturalism, opposes superstition,
argues for toleration and the subordination of religion to the state,
and pronounces in favor of qualified democracy. Liberalism is perhaps
the most characteristic political philosophy of the Enlightenment, and
Spinoza, in this text primarily, is one of its originators.



However, John Locke's *Second Treatise of*
*Government* (1690) is the classical source of modern liberal
political theory. In his *First Treatise of Government*, Locke
attacks Robert Filmer's *Patriarcha* (1680), which
epitomizes the sort of political theory the Enlightenment opposes.
Filmer defends the right of kings to exercise absolute authority over
their subjects on the basis of the claim that they inherit the
authority God vested in Adam at creation. Though Locke's
assertion of the natural freedom and equality of human beings in the
*Second Treatise* is starkly and explicitly opposed to
Filmer's view, it is striking that the cosmology underlying
Locke's assertions is closer to Filmer's than to
Spinoza's. According to Locke, in order to understand the nature
and source of legitimate political authority, we have to understand
our relations in the state of nature. Drawing upon the natural law
tradition, Locke argues that it is evident to our natural reason that
we are all absolutely subject to our Lord and Creator, but that, in
relation to each other, we exist naturally in a state of equality
"wherein all the power and jurisdiction is reciprocal, no one
having more than another" (*Second Treatise*, SS4).
We also exist naturally in a condition of freedom, insofar as we may
do with ourselves and our possessions as we please, within the
constraints of the fundamental law of nature. The law of nature
"teaches all mankind ... that, being all equal and
independent, no one ought to harm another in his life, health,
liberty, or possessions" (SS6). That we are governed in our
natural condition by such a substantive moral law, legislated by God
and known to us through our natural reason, implies that the state of
nature is not Hobbes' war of all against all. However, since
there is lacking any human authority over all to judge of disputes and
enforce the law, it is a condition marred by
"inconveniencies", in which possession of natural freedom,
equality and possessions is insecure. According to Locke, we
rationally quit this natural condition by contracting together to set
over ourselves a political authority, charged with promulgating and
enforcing a single, clear set of laws, for the sake of guaranteeing
our natural rights, liberties and possessions. The civil, political
law, founded ultimately upon the consent of the governed, does not
cancel the natural law, according to Locke, but merely serves to draw
that law closer. "[T]he law of nature stands as an eternal rule
to all men" (SS135). Consequently, when established
political power violates that law, the people are justified in
overthrowing it. Locke's argument for the right to revolt
against a government that opposes the purposes for which legitimate
government is taken by some to justify the political revolution in the
context of which he writes (the English revolution) and, almost a
hundred years later, by others to justify the American revolution as
well.



Though Locke's liberalism has been tremendously influential, his
political theory is founded on doctrines of natural law and religion
that are not nearly as evident as Locke assumes. Locke's
reliance on the natural law tradition is typical of Enlightenment
political and moral theory. According to the natural law tradition, as
the Enlightenment makes use of it, we can know through the use of our
unaided reason that we all - all human beings, universally
- stand in particular moral relations to each other. The claim
that we can apprehend through our unaided reason a *universal*
moral order exactly because moral qualities and relations (in
particular human freedom and equality) belong to the nature of things,
is attractive in the Enlightenment for obvious reasons. However, as
noted above, the scientific apprehension of nature in the period does
not support, and in fact opposes, the claim that the alleged moral
qualities and relations (or, indeed, that *any* moral qualities
and relations) are *natural*. According to a common
Enlightenment assumption, as humankind clarifies the laws of nature
through the advance of natural science and philosophy, the true moral
and political order will be revealed with it. This view is expressed
explicitly by the *philosophe* Marquis de Condorcet, in his
*Sketch for a Historical Picture of the Progress of the Human
Mind* (published posthumously in 1795 and which, perhaps better
than any other work, lays out the paradigmatically Enlightenment view
of history of the human race as a continual progress to perfection).
But, in fact, advance in knowledge of the laws of nature in the
science of the period does not help with discernment of a natural
political or moral order. This asserted relationship between natural
scientific knowledge and the political and moral order is under great
stress already in the Enlightenment. With respect to Lockean
liberalism, though his assertion of the moral and political claims
(natural freedom, equality, et cetera) continues to have considerable
force for us, the grounding of these claims in a religious cosmology
does not. The question of how to ground our claims to natural freedom
and equality is one of the main philosophical legacies of the
Enlightenment.



The rise and development of liberalism in Enlightenment political
thought has many relations with the rise of the mercantile class (the
bourgeoisie) and the development of what comes to be called
"civil society", the society characterized by work and
trade in pursuit of private property. Locke's *Second
Treatise* contributes greatly to the project of articulating a
political philosophy to serve the interests and values of this
ascending class. Locke claims that the end or purpose of political
society is the preservation and protection of property (though he
defines property broadly to include not only external property but
life and liberties as well). According to Locke's famous
account, persons acquire rightful ownership in external things that
are originally given to us all by God as a common inheritance,
independently of the state and prior to its involvement, insofar as we
"mix our labor with them". The civil freedom that Locke
defines, as something protected by the force of political laws, comes
increasingly to be interpreted as the freedom to trade, to exchange
without the interference of governmental regulation. Within the
context of the Enlightenment, economic freedom is a salient
interpretation of the individual freedom highly valued in the period.
Adam Smith, a prominent member of the Scottish Enlightenment,
describes in his *An Inquiry into the Nature and Causes of the
Wealth of Nations* (1776) some of the laws of civil society, as a
sphere distinct from political society as such, and thus contributes
significantly to the founding of political economy (later called
merely "economics"). His is one of many voices in the
Enlightenment advocating for free trade and for minimal government
regulation of markets. The trading house floor, in which people of
various nationalities, languages, cultures, religions come together
and trade, each in pursuit of his own self-interest, but, through this
pursuit, supplying the wants of their respective nations and
increasing its wealth, represents for some Enlightenment thinkers the
benign, peaceful, universal rational order that they wish to see
replace the violent, confessional strife that characterized the
then-recent past of Europe.



However, the liberal conception of the government as properly
protecting economic freedom of citizens and private property comes
into conflict in the Enlightenment with the value of democracy. James
Madison confronts this tension in the context of arguing for the
adoption of the U.S. Constitution (in his Federalist #10). Madison
argues that popular government (pure democracy) is subject to the evil
of factions; in a pure democracy, a majority bound together by a
private interest, relative to the whole, has the capacity to impose
its particular will on the whole. The example most on Madison's
mind is that those without property (the many) may seek to bring about
governmental re-distribution of the property of the propertied class
(the few), perhaps in the name of that other Enlightenment ideal,
equality. If, as in Locke's theory, the government's
protection of an individual's freedom is encompassed within the
general end of protecting a person's property, then, as Madison
argues, the proper form of the government cannot be pure democracy,
and the will of the people must be officially determined in some other
way than by directly polling the people.



Jean-Jacques Rousseau's political theory, as presented in his
*On the Social Contract* (1762), presents a contrast to the
Lockean liberal model. Though commitment to the political ideals of
freedom and equality constitutes a common ground for Enlightenment
political philosophy, it is not clear not only how these values have a
home in nature as Enlightenment science re-conceives it, but also how
concretely to interpret each of these ideals and how properly to
balance them against each other. Contrary to Madison, Rousseau argues
that direct (pure) democracy is the only form of government in which
human freedom can be realized. Human freedom, according to
Rousseau's interpretation, is possible only through governance
according to what he calls "the general will," which is
the will of the body politic, formed through the original contract,
concretely determined in an assembly in which all citizens
participate. Rousseau's account intends to avert the evils of
factions by structural elements of the original contract. The contract
consists in the self-alienation by each associate of all rights and
possessions to the body politic. Because each alienates all, each is
an equal member of the body politic, and the terms and conditions are
the same for all. The emergence of factions is avoided insofar as the
good of each citizen is, and is understood to be, equally (because
wholly) dependent on the general will. Legislation supports this
identification with the general will by preserving the original
equality established in the contract, prominently through maintaining
a measure of economic equality. Rousseau's account of the ideal
relation of the individual citizen to the state differs from
Locke's; in Rousseau's account, the individual must be
actively engaged in political life in order to maintain the
identification of his supremely authoritative will with the general
will, whereas in Locke the emphasis is on the limits of governmental
authority with respect to the expressions of the individual will.
Though Locke's liberal model is more representative of the
Enlightenment in general, Rousseau's political theory, which in
some respects presents a revived classical model modified within the
context of Enlightenment values, in effect poses many of the enduring
questions regarding the meaning and interpretation of political
freedom and equality within the modern state.



Both Madison and Rousseau, like most political thinkers of the period,
are influenced by Baron de Montesquieu's *The Spirit of the
Laws* (1748), which is one of the founding texts of modern
political theory. Though Montesquieu's treatise belongs to the
tradition of liberalism in political theory, given his scientific
approach to social, legal and political systems, his influence extends
beyond this tradition. Montesquieu argues that the system of
legislation for a people varies appropriately with the particular
circumstances of the people. He provides specific analysis of how
climate, fertility of the soil, population size, et cetera, affect
legislation. He famously distinguishes three main forms of
governments: republics (which can either be democratic or
aristocratic), monarchies and despotisms. He describes leading
characteristics of each. His argument that functional democracies
require the population to possess civic virtue in high measure, a
virtue that consists in valuing public good above private interest,
influences later Enlightenment theorists, including both Rousseau and
Madison. He describes the threat of factions to which Madison and
Rousseau respond in different (indeed opposite) ways. He provides the
basic structure and justification for the balance of political powers
that Madison later incorporates into the U.S. Constitution.



It is striking how unenlightened many of the Enlightenment's
celebrated thinkers are concerning issues of race and of gender
(regarding race, see *Race and Enlightenment: A Reader*, edited
by Emmanuel Chukwudi Eze). For all the public concern with the
allegedly universal "rights of man" in the Enlightenment,
the rights of women and of non-white people are generally overlooked
in the period. (Mary Wollstonecraft's *Vindication of the
Rights of Woman* (1792) is a noteworthy exception.) When
Enlightenment thinkers do turn their attention to the social standing
of women or of non-white people, they tend to spout unreasoned
prejudice. Moreover, while the philosophies of the Enlightenment
generally aspire or pretend to universal truth, unattached to
particular time, place or culture, Enlightenment writings are rife
with rank ethno- and Eurocentrism, often explicit.



In the face of such tensions within the Enlightenment, one response is
to affirm the power of the Enlightenment to improve humanity and
society long beyond the end of the eighteenth century, indeed, down to
the present day and into the future. This response embraces the
Enlightenment and interprets more recent emancipation movements and
achievement of recognition of the rights and dignity of traditionally
oppressed and marginalized groups as expressions of Enlightenment
ideals and aspirations. Critics of the Enlightenment respond
differently to such tensions. Critics see them as symptoms of
disorder, ideology, perversity, futility or falsehood that afflict the
very core of the Enlightenment itself. (See James Schmidt's
"What Enlightenment Project?" for discussion of critics of
the Enlightenment.) Famously, Adorno and Horkheimer interpret Nazi
death camps as the result of "the dialectic of the
Enlightenment", as what historically becomes of the supremacy of
instrumental reason asserted in the Enlightenment. As another example,
we may point to some post-modern feminists, who argue, in opposition
to the liberal feminists who embrace broadly Enlightenment ideals and
conceptions, that the essentialism and universalism associated with
Enlightenment ideals are both false and intrinsically hostile to the
aspirations to self-realization of women and of other traditionally
oppressed groups. (See Strickland and the essays in Akkerman and
Stuurman.) This entry is not the place to delineate strains of
opposition to the Enlightenment, but it is worth noting that
post-Enlightenment social and political struggles to achieve equality
or recognition for traditionally marginalized or oppressed groups are
sometimes self-consciously grounded in the Enlightenment and sometimes
marked by explicit opposition to the Enlightenment's conceptions
or presuppositions.


### 2.2 Ethical Theory



Many of the leading issues and positions of contemporary philosophical
ethics take shape within the Enlightenment. Prior to the Enlightenment
in the West, ethical reflection begins from and orients itself around
religious doctrines concerning God and the afterlife. The highest good
of humanity, and, accordingly, the content and grounding of moral
duties, are conceived in immediately religious terms. During the
Enlightenment, this changes, certainly within philosophy, but to some
significant degree, within the population of western society at large.
As the processes of industrialization, urbanization, and dissemination
of education advance in this period, happiness in this life, rather
than union with God in the next, becomes the highest end for more and
more people. Also, the violent religious wars that bloody Europe in
the early modern period motivate the development of secular,
this-worldly ethics, insofar as they indicate the failure of religious
doctrines concerning God and the afterlife to establish a stable
foundation for ethics. In the Enlightenment, philosophical thinkers
confront the problem of developing ethical systems on a secular,
broadly naturalistic basis for the first time since the rise of
Christianity eclipsed the great classical ethical systems. However,
the changes in our understanding of nature and cosmology, effected by
modern natural science, make recourse to the systems of Plato and
Aristotle problematic. The Platonic identification of the good with
the real and the Aristotelian teleological understanding of natural
things are both difficult to square with the Enlightenment conception
of nature. The general philosophical problem emerges in the
Enlightenment of how to understand the source and grounding of ethical
duties, and how to conceive the highest good for human beings, within
a secular, broadly naturalistic context, and within the context of a
transformed understanding of the natural world.



In ethical thought, as in political theory, Hobbes' thought is
an important provocation in the Enlightenment. Hobbes understands what
is good, as the end of human action, to be "whatsoever is the
object of any man's appetite or desire," and evil to be
"the object of his hate, and aversion," "there being
nothing simply and absolutely so; nor any common rule of good and
evil, to be taken from the nature of the objects themselves"
(*Leviathan*, chapter 6). Hobbes' conception of human
beings as fundamentally motivated by their perception of what is in
their own best interest implies the challenge, important for
Enlightenment moral philosophy, to construct moral duties of justice
and benevolence out of such limited materials. The basis of human
action that Hobbes posits is immediately intelligible and even shared
with other animals to some extent; a set of moral duties constructed
on this basis would also be intelligible, de-mystified, and fit within
the larger scheme of nature. Bernard Mandeville is sometimes grouped
with Hobbes in the Enlightenment, especially by critics of them both,
because he too, in his popular *Fable of the Bees; or, Private
Vices, Public Benefits* (1714), sees people as fundamentally
motivated by their perceived self-interest, and then undertakes to
tell a story about how moral virtue, which involves conquering
one's own appetite and serving the interests of others, can be
understood to arise on this basis.



Samuel Clarke, an influential rationalist British thinker early in the
Enlightenment, undertakes to show in his *Discourse concerning the
Unchangeable Obligations of Natural Religion* (1706), against
Hobbes, that the absolute difference between moral good and moral evil
lies in the immediately discernible nature of things, independently of
any compacts or positive legislation by God or human beings. Clarke
writes that "in men's dealing ... one with another,
it is undeniably more fit, absolutely and in the nature of the thing
itself, that all men should endeavor to promote the universal good and
welfare of all; than that all men should be continually contriving the
ruin and destruction of all". Likewise for the rest of what
morality enjoins upon us. According to Clarke, that some actions
(those we call morally good or required) are "fit to be
done" and others not fit is grounded upon the immediately
evident relations in which things stand to each other in nature, just
as "the proportions of lines or numbers" are evident to
the rational perception of a reasonable being. Similarly, Christian
Wolff's rationalist practical philosophy also grounds moral
duties in an objective rational order. However, the objective quality
on which moral requirements are grounded for Wolff is not the
"fitness" of things to be done but rather their
perfection. Wolff counts as a founder of the *Aufklarung*
in part because of his attempted derivation of ethical duties from an
order of perfection in things, discernable through reason,
independently of divine commands.



Rationalist ethics so conceived faces the following obstacles in the
Enlightenment. First, as implied above, it becomes increasingly
implausible that the objective, mind-independent order is really as
rationalist ethicists claim it to be. Second, even if the objective
realm were ordered as the rationalist claims, it remains unclear how
this order gives rise (on its own, as it were) to obligations binding
on our wills. David Hume famously exposes the fallacy of deriving a
prescriptive statement (that one ought to perform some action) from a
description of how things stand in relation to each other in nature.
Prima facie, there is a gap between the rationalist's objective
order and a set of prescriptions binding on our wills; if a supreme
legislator must be re-introduced in order to make the conformity of
our actions to that objective order binding on our wills, then the
alleged existence of the objective moral order does not do the work
the account asks of it in the first place.



Alongside the rationalist strand of ethical philosophy in the
Enlightenment, there is also a very significant empiricist strand.
Empirical accounts of moral virtue in the period are distinguished,
both by grounding moral virtue on an empirical study of human nature,
and by grounding cognition of moral duties and moral motivation in
human sensibility, rather than in reason. The Third Earl of
Shaftesbury, author of the influential work *Characteristics of
Men, Manners, Opinions, Times* (1711), is a founding figure of the
empiricist strand. Shaftesbury, like Clarke, is provoked by
Hobbes' egoism to provide a non-egoistic account of moral
virtue. Shaftesbury conceives the core notion of the goodness of
things teleologically: something is good if it contributes to the
well-being or furtherance of the system of which it is a part.
Individual animals are members of species, and therefore they are good
as such insofar as they contribute to the well-being of the species of
which they are a part. Thus, the good of things, including human
beings, for Shaftesbury as for Clarke, is an objective quality that is
knowable through reason. However, though we can know what is good
through reason, Shaftesbury maintains that reason alone is not
sufficient to motivate human action. Shaftesbury articulates the
structure of a distinctively human moral sensibility. Moral
sensibility depends on the faculty of reflection. When we reflect on
first-order passions such as gratitude, kindness and pity, we find
ourselves approving or liking them and disapproving or disliking their
opposites. By virtue of our receptivity to such feelings, we are
capable of virtue and have a sense of right and wrong. In this way,
Shaftesbury defines the moral sense that plays a significant role in
the theories of subsequent Enlightenment thinkers such as Francis
Hutcheson and David Hume.



In the rationalist tradition, the conflict within the breast of the
person between the requirements of morality and self-interest is
canonically a conflict between the person's reason and her
passions. Shaftesbury's identification of a moral sentiment in
the nature of humanity renders this a conflict within sensibility
itself, a conflict between different sentiments, between a
self-interested sentiment and an unegoistic sentiment. Though both
Shaftesbury and Hutcheson, no less than Clarke, oppose Hobbes's
egoism, it is nonetheless true that the doctrine of moral sensibility
softens moral demands, so to speak. Doing what is morally right or
morally good is intrinsically bound up with a distinctive kind of
pleasure on their accounts. It is significant that both Shaftesbury
and Hutcheson, the two founders of modern moral sense theory,
articulate their ethical theory in conjunction with an aesthetic
theory. Arguably the pleasure we feel in the apprehension of something
beautiful is *disinterested pleasure*. Our susceptibility to
aesthetic pleasure can be taken to reveal that we apprehend and
respond to objective (or, anyway, universal) values, not only or
necessarily on the basis of reason, but through our natural
sensibility instead. Thus, aesthetics, as Shaftesbury and Hutcheson
independently develop an account of it, gives encouragement to their
doctrines of moral sensibility. But an account of moral virtue, unlike
aesthetics, requires an account of moral *motivation*. As noted
above, both Shaftesbury and Hutcheson want to do justice to the idea
that proper moral motivation is not the pursuit of pleasure, even
disinterested pleasure, but rather an immediate response to the
perception of moral value. The problem of giving a satisfying account
of moral motivation is a difficult one for empiricist moral
philosophers in the Enlightenment.



While for Shaftesbury, at the beginning of the moral sense tradition,
moral sense tracks a mind-independent order of value, David Hume,
motivated in part by a more radical empiricism, is happy to let the
objective order go. We have no access through reason to an independent
order of value which moral sense would track. For Hume, morality is
founded completely on our sentiments. Hume is often regarded as the
main originator of so-called "ethical subjectivism",
according to which moral judgments or evaluations (regarding actions
or character) do not make claims about independent facts but merely
express the subject's feelings or attitudes with respect to
actions or character. Such subjectivism is relieved of the difficult
task of explaining how the objective order of values belongs to the
natural world as it is being reconceived by natural science in the
period; however, it faces the challenge of explaining how error and
disagreement in moral judgments and evaluations are possible.
Hume's account of the standards of moral judgment follows that
of Hutcheson in relying centrally on the "natural"
responses of an ideal observer or spectator.



Hume's ethics is exemplary of philosophical ethics in the
Enlightenment by virtue of its belonging to the attempt to provide a
new, empirically grounded science of human nature, free of theological
presuppositions. As noted above, the attempts by the members of the
French Enlightenment to present a new understanding of human nature
are strongly influenced by Locke's "sensationalism",
which, radicalized by Condillac, amounts to the attempt to base all
contents and faculties of the human mind on the senses. Typically, the
French *philosophes* draw more radical or iconoclastic
implications from the new "science of man" than English or
Scottish Enlightenment figures. Claude-Adrien Helvetius
(1715-1771) is typical here. In *De
l'esprit* (1758), Helvetius follows the
Lockean sensationalism of Condillac and pairs it with the claim that
human beings are motivated in their actions only by the natural desire
to maximize their own pleasure and minimize their pain. *De
l'esprit*, though widely read, gives rise to strong
negative reactions in the time, both by political and religious
authorities (the Sorbonne, the Pope and the Parlement of Paris all
condemn the book) and by prominent fellow *philosophes*, in
great part because Helvetius's psychology seems to
critics to render moral imperatives and values without basis, despite
his best attempts to derive them. Helvetius attempts to ground
the moral equality of all human beings by portraying all human beings,
whatever their standing in the social hierarchy, whatever their
special talents and gifts, as equally products of the nature we share
plus the variable influences of education and social environment. But,
to critics, Helvetius's account portrays all human beings
as equal only by virtue of portraying all as equally worthless
(insofar as the claim to equality is grounded on all being equally
determined by external factors). However, Helvetius's
ideas, in *De l'esprit* as well as in its
posthumously published sequel *De l'homme* (1772), exert
a great deal of influence, especially his case for the role of
pleasure and pain in human motivation and the role of education and
social incentives in shaping individuals into contributors to the
social good. Helvetius is sometimes regarded as the father of
modern utilitarianism through his articulation of the greatest
happiness principle and through his influence on Bentham.



Helvetius is typical in the respect that he is radical in the
revisions he proposes, not in common moral judgments or customs of the
time, but rather regarding the philosophical grounding of those
judgments and customs. But there are some philosophers in the
Enlightenment who are radical in the revisions they propose regarding
the content of ethical judgments themselves. The Marquis de Sade is
merely the most notorious example, among a set of Enlightenment
figures (including also the Marquis de Argens and Diderot himself in
some of his writings) who, within the context of the new naturalism
and its emphasis on the pursuit of pleasure, celebrate the avid
pursuit of sexual pleasure and explicitly challenge the sexual mores,
as well as the wider morality, of their time. The more or less
fictionalized, philosophically self-conscious "libertine"
is one significant expression of Enlightenment ethical thought.



If the French Enlightenment tends to advance this-worldly happiness as
the highest good for human beings more insistently than the
Enlightenment elsewhere, then Rousseau's voice is, in this as in
other respects, a discordant voice in that context. Rousseau advances
the cultivation and realization of *human freedom* as the
highest end for human beings and thereby gives expression to another
side of Enlightenment ethics. As Rousseau describes it, the capacity
for individual self-determination puts us in a problematic relation to
our natural desires and inclinations and to the realm of nature
generally, insofar as that realm is constituted by mechanistic
causation. Though Rousseau places a great deal of emphasis on human
freedom, and makes significant contributions to our understanding of
ourselves as free, he does not address very seriously the problem of
the place of human freedom in the cosmos as it is conceived within the
context of Enlightenment naturalism.



However, Rousseau's writings help Kant to the articulation of a
practical philosophy that addresses many of the tensions in the
Enlightenment. Kant follows Rousseau, and disagrees with empiricism in
ethics in the period, in emphasizing human freedom, rather than human
happiness, as the central orienting concept of practical philosophy.
Though Kant presents the moral principle as a principle of practical
reason, his ethics also disagrees significantly with rationalist
ethics in the period. According to Kant, rationalists such as Wolff,
insofar as they take moral prescriptions to follow from an end given
to the will (in Wolff's case, the end of perfection), do not
understand us as autonomous in our moral activity. Through
interpreting the faculty of the will itself as practical reason, Kant
understands the moral principle as internally legislated, thus as not
only compatible with freedom, but as equivalent to the principle of a
free will, as a principle of autonomy. As noted above, rationalists in
ethics in the period are challenged to explain how the objective moral
order which reason in us allegedly discerns gives rise to valid
prescriptions binding on our wills (the gap between *is* and
*ought*). For Kant, the moral order is not independent of our
will, but rather represents the formal constraints of willing as such.
Kant's account thus both avoids the is-ought gap and interprets
moral willing as expressive of our freedom.



Moreover, by virtue of his interpretation of the moral principle as
the principle of pure practical reason, Kant is able to redeem the
ordinary sense of moral requirements as over-riding, as potentially
opposed to the claims of one's happiness, and thus as different
in kind from the deliverances of prudential reasoning. This ordinary
sense of moral requirements is not easily accommodated within the
context of Enlightenment empiricism and naturalism. Kant's stark
dichotomy between a person's practical reason and her sensible
nature is strongly criticized, both by the subsequent Romantic
generation and in the contemporary context; but this dichotomy is
bound up with an important benefit of Kant's view - much
promoted by Kant himself - within the context of the
Enlightenment. Elaborated in the context of Kant's idealism as a
contrast between the "realm of freedom" and the
"realm of nature", the dichotomy enables Kant's
proposed solution to the conflict between freedom and nature that
besets Enlightenment thought. As noted above, Kant argues that the
application of the causal principle is restricted to the realm of
nature, thus making room for freedom, compatibly with the causal
determination of natural events required by scientific knowledge.
Additionally, Kant attempts to show that morality "leads
ineluctably to" religious belief (in the supersensible objects
of God and of the immortal soul) while being essentially not founded
on religious belief, thus again vindicating the ordinary understanding
of morality while still furthering Enlightenment values and
commitments.


### 2.3 Religion and the Enlightenment



Though the Enlightenment is sometimes represented as the enemy of
religion, it is more accurate to see it as critically directed against
various (arguably contingent) features of religion, such as
superstition, enthusiasm, fanaticism and supernaturalism. Indeed the
effort to discern and advocate for a religion purified of such
features - a "rational" or "natural"
religion - is more typical of the Enlightenment than opposition
to religion as such. Even Voltaire, who is perhaps the most
persistent, powerful, vocal Enlightenment critic of religion, directs
his polemic mostly against the Catholic Church in France -
"*l'infame*" in his famous sign-off in
his letters, "*Ecrasez
l'infame*" ("Crush the infamous")
refers to the Church, not to religion as such. However, controversy
regarding the truth-value or reasonableness of religious belief in
general, Christian belief in particular, and controversy regarding the
proper place of religion in society, occupies a particularly central
place in the Enlightenment. It's as if the terrible, violent
confessional strife in the early modern period in Europe, the bloody
drawn-out wars between the Christian sects, was removed to the
intellectual arena in the Enlightenment and became a set of more
general philosophical controversies.



Alongside the rise of the new science, the rise of Protestantism in
western Christianity also plays an important role in generating the
Enlightenment. The original Protestants assert a sort of individual
liberty with respect to questions of faith against the paternalistic
authority of the Church. The "liberty of conscience", so
important to Enlightenment thinkers in general, and asserted against
all manner of paternalistic authorities (including Protestant),
descends from this Protestant assertion. The original Protestant
assertion initiates a crisis of authority regarding religious belief,
a crisis of authority that, expanded and generalized and even, to some
extent, secularized, becomes a central characteristic of the
Enlightenment spirit. The original Protestant assertion against the
Catholic Church bases itself upon the authority of scripture. However,
in the Enlightenment, the authority of scripture is strongly
challenged, especially when taken literally. Developing natural
science renders acceptance of a literal version of the Bible
increasingly untenable. But authors such as Spinoza (in his
*Tractatus Theologico-Politicus*) present ways of interpreting
scripture according to its spirit, rather than its letter, in order to
preserve its authority and truth, thus contributing to the
Enlightenment controversy of whether some rationally purified version
of the religion handed down in the culture belongs to the true
philosophical representation of the world or not; and, if so, what its
content is.



It is convenient to discuss religion in the Enlightenment by
presenting four characteristic forms of Enlightenment religion in
turn: deism, religion of the heart, fideism and atheism.



*Deism*. Deism is the form of religion most associated with the
Enlightenment. According to deism, we can know by the natural light of
reason that the universe is created and governed by a supreme
intelligence; however, although this supreme being has a plan for
creation from the beginning, the being does not interfere with
creation; the deist typically rejects miracles and reliance on special
revelation as a source of religious doctrine and belief, in favor of
the natural light of reason. Thus, a deist typically rejects the
divinity of Christ, as repugnant to reason; the deist typically
demotes the figure of Jesus from agent of miraculous redemption to
extraordinary moral teacher. Deism is the form of religion fitted to
the new discoveries in natural science, according to which the cosmos
displays an intricate machine-like order; the deists suppose that the
supposition of God is necessary as the source or author of this order.
Though not a deist himself, Isaac Newton provides fuel for deism with
his argument in his *Opticks* (1704) that we must infer from
the order and beauty in the world to the existence of an intelligent
supreme being as the cause of this order and beauty. Samuel Clarke,
perhaps the most important proponent and popularizer of Newtonian
philosophy in the early eighteenth century, supplies some of the more
developed arguments for the position that the correct exercise of
unaided human reason leads inevitably to the well-grounded belief in
God. He argues that the Newtonian physical system implies the
existence of a transcendent cause, the creator God. In his first set
of Boyle lectures, *A Demonstration of the Being and Attributes of
God* (1705), Clarke presents the metaphysical or "argument
*a priori*" for God's existence. This argument
concludes from the rationalist principle that whatever exists must
have a sufficient reason or cause of its existence to the existence of
a transcendent, necessary being who stands as the cause of the chain
of natural causes and effects. Clarke also supports the empirical
argument from design, the argument that concludes from the evidence of
order in nature to the existence of an intelligent author of that
order. In his second set of Boyle lectures, *A Discourse Concerning
the Unchangeable Obligations of Natural Religion* (1706), Clarke
argues as well that the moral order revealed to us by our natural
reason requires the existence of a divine legislator and an afterlife,
in which the supreme being rewards virtue and punishes vice. In his
Boyle lectures, Clarke argues directly against the deist philosophy
and maintains that what he regards as the one true religion,
Christianity, is known as such on the basis of miracles and special
revelation; still, Clarke's arguments on the topic of natural
religion are some of the best and most widely-known arguments in the
period for the general deist position that natural philosophy in a
broad sense grounds central doctrines of a universal religion.



Enlightenment deism first arises in England. In *On the
Reasonableness of Christianity* (1695), Locke aims to establish
the compatibility of reason and the teachings of Christianity. Though
Locke himself is (like Newton, like Clarke) not a deist, the major
English deists who follow (John Toland, *Christianity Not
Mysterious* [1696]); Anthony Collins, *A Discourse of
Freethinking* [1713]; Matthew Tindal, *Christianity as Old as
Creation* [1730]) are influenced by Locke's work. Voltaire
carries deism across the channel to France and advocates for it there
over his long literary career. Toward the end-stage, the farcical
stage, of the French Revolution, Robespierre institutes a form of
deism, the so-called "Cult of the Supreme Being", as the
official religion of the French state. Deism plays a role in the
founding of the American republic as well. Many of the founding
fathers (Jefferson, Franklin, Madison, Paine) author statements or
tracts that are sympathetic to deism; and their deistic sympathies
influence the place given (or not given) to religion in the new
American state that they found.



*Religion of the Heart*. Opposition to deism derives sometimes
from the perception of it as coldly rationalistic. The God of the
deists, arrived at through a priori or empirical argument and referred
to as the Prime Mover or Original Architect, is often perceived as
distant and unconcerned with the daily struggles of human existence,
and thus as not answering the human needs from which religion springs
in the first place. Some important thinkers of the Enlightenment
- notably Shaftesbury and Rousseau - present religion as
founded on natural human sentiments, rather than on the operations of
the intellect. Rousseau has his Savoyard Vicar declare, in his
Profession of Faith in *Emile* (1762), that the idea of
worshiping a beneficent deity arose in him initially as he reflected
on his own situation in nature and his "heart began to glow with
a sense of gratitude towards the author of our being". The
Savoyard Vicar continues: "I adore the supreme power, and melt
into tenderness at his goodness. I have no need to be taught
artificial forms of worship; the dictates of nature are sufficient. Is
it not a natural consequence of self-love to honor those who protect
us, and to love such as do us good?" This "natural"
religion - opposed to the "artificial" religions
enforced in the institutions - is often classed as a form of
deism. But it deserves separate mention, because of its grounding in
natural human sentiments, rather than in reason or in metaphysical or
natural scientific problems of cosmology.



*Fideism*. Deism or natural religion of various sorts tends to
rely on the claim that reason or human experience supports the
hypothesis that there is a supreme being who created or authored the
world. In one of the most important philosophical texts on natural
religion to appear during the Enlightenment, David Hume's
*Dialogues Concerning Natural Religion* (published posthumously
in 1779), this supposition is criticized relentlessly, incisively and
in detail. Naturally, the critical, questioning attitude
characteristic of the Enlightenment in general is directed against the
arguments on which natural religion is based. In Part Nine of the
*Dialogues,* Samuel Clarke's "argument a
priori" (as defended by the character Demea) is dispatched
fairly quickly, but with a battery of arguments. But Hume is mainly
concerned in the *Dialogues* with the other major pillar of
natural religion in the Enlightenment, the "empirical"
argument, the teleological argument or the argument from design.
Cleanthes, the character who advances the design argument in the
dialogue, proceeds from the rule for empirical reasoning that like
effects prove like causes. He reasons that, given the resemblance
between nature, which displays in many respects a "curious
adaptation of means to ends", and a man-made machine, we must
infer the cause of nature to be an intelligence like ours, though
greater in proportion as nature surpasses in perfection the products
of human intelligence. Philo, the skeptical voice in the
*Dialogues*, presses Cleanthes' argument on many fronts.
He points out that the argument is only as strong as the similarity
between nature or parts of nature and man-made machines, and further,
that a close scrutiny reveals that analogy to be weak. Moreover,
according to the principle of the argument, the stronger the evidence
for an author (or authors) of nature, the *more like us* that
author (or authors) should be taken to be. Consequently, according to
Philo, the argument does not support the conclusion that *God*
exists, taking God to be unitary, infinite, perfect, et cetera. Also,
although the existence of evil and disorder in nature may serve
actually to strengthen the case for the argument, given the disorder
in human creations as well, the notion that God authors evil and
disorder is disturbing. If one denies that there is disorder and evil
in nature, however implausibly, the effect is to emphasize again the
dissimilarity between nature and human products and thus weaken the
central basis of the argument. With these and other considerations,
Philo puts the proponent of the empirical argument in a difficult
dialectical position. But Cleanthes is not moved. He holds the
inference from the phenomenon of the curious adaptation of means to
ends in nature to the existence of an intelligent and beneficent
author to be so natural as to be impervious to the philosophical
cavils raised by Philo. And, in the ambiguous conclusion of the work,
Philo seems to agree. Though Hume himself seems to have been an
atheist, one natural way to take the upshot of his *Dialogues*
is that religious belief is so "natural" to us that
rational criticism cannot unseat it. The ambiguous upshot of the work
can be taken to be the impotence of rational criticism in the face of
religious belief, rather than the illegitimacy of religious belief in
the face of rational criticism. This tends toward fideism, the view
according to which religious faith maintains its truth over against
philosophical reasoning, which opposes but cannot defeat it. Fideism
is most often associated with thinkers whose beliefs run contrary to
the trends of the Enlightenment (Blaise Pascal, Johann-Georg Hamann,
Soren Kierkegaard), but the skeptical strain in the
Enlightenment, from Pierre Bayle through David Hume, expresses itself
not only in atheism, but also in fideism.



*Atheism*. Atheism is more present in the French Enlightenment
than elsewhere. In the writings of Denis Diderot, atheism is partly
supported by an expansive, dynamic conception of nature. According to
the viewpoint developed by Diderot, we ought to search for the
principles of natural order within natural processes themselves, not
in a supernatural being. Even if we don't yet know the internal
principles for the ordering and development of natural forms, the
appeal to a transcendent author of such things is reminiscent, to
Diderot's ear, of the appeal to Aristotelian "substantial
forms" that was expressly rejected at the beginning of modern
science as explaining nothing. The appeal to a transcendent author
does not extend our understanding, but merely marks and fixes the
limits of it. Atheism (combined with materialism) in the French
Enlightenment is perhaps most identified with the Baron
d'Holbach, whose *System of Nature* (1770) generated a
great deal of controversy at the time for urging the case for atheism
explicitly and emphatically. D'Holbach's system of nature
is strongly influenced by Diderot's writings, though it displays
less subtlety and dialectical sophistication. Though most
Enlightenment thinkers hold that morality requires religion, in the
sense that morality requires belief in a transcendent law-giver and in
an after-life, d'Holbach (influenced in this respect by Spinoza,
among others) makes the case for an ethical naturalism, an ethics that
is free of any reference to a supernatural grounding or aspiration.
Like Helvetius before him, d'Holbach presents an ethics
in which virtue consists in enlightened self-interest. The
metaphysical background of the ethics he presents is deterministic
materialism. The Prussian enlightened despot, Frederick the Great,
famously criticizes d'Holbach's book for exemplifying the
incoherence that troubles the Enlightenment generally: while
d'Holbach provides passionate moral critiques of existing
religious and social and political institutions and practices, his own
materialist, determinist conception of nature allows no place for
moral "oughts" and prescriptions and values.


## 3. The Beautiful: Aesthetics in the Enlightenment



Modern systematic philosophical aesthetics not only first emerges in
the context of the Enlightenment, but also flowers brilliantly there.
As Ernst Cassirer notes, the eighteenth century not only thinks of
itself as the "century of philosophy", but also as
"the age of criticism," where criticism is centrally
(though not only) art and literary criticism (Cassirer 1932, 255).
Philosophical aesthetics flourishes in the period because of its
strong affinities with the tendencies of the age. Alexander
Baumgarten, the German philosopher in the school of Christian Wolff,
founds systematic aesthetics in the period, in part through giving it
its name. "Aesthetics" is derived from the Greek word for
"senses", because for Baumgarten a science of the
beautiful would be a science of the sensible, a science of sensible
cognition. The Enlightenment in general re-discovers the value of the
senses, not only in cognition, but in human lives in general, and so,
given the intimate connection between beauty and human sensibility,
the Enlightenment is naturally particularly interested in aesthetics.
Also, the Enlightenment includes a general recovery and affirmation of
the value of pleasure in human lives, against the tradition of
Christian asceticism, and the flourishing of the arts, of the
criticism of the arts and of the philosophical theorizing about
beauty, promotes and is promoted by this recovery and affirmation. The
Enlightenment also enthusiastically embraces the discovery and
disclosure of rational order in nature, as manifest most clearly in
the development of the new science. It seems to many theorists in the
Enlightenment that the faculty of taste, the faculty by which we
discern beauty, reveals to us some part of this order, a distinctive
harmony, unities amidst variety. Thus, in the phenomenon of aesthetic
pleasure, human sensibility discloses to us rational order, thus
binding together two enthusiasms of the Enlightenment.


### 3.1 French Classicism and German Rationalism



In the early Enlightenment, especially in France, the emphasis is upon
the discernment of an objective rational order, rather than upon the
subject's sensual aesthetic pleasure. Though Descartes'
philosophical system does not include a theory of taste or of beauty,
his mathematical model of the physical universe inspires the
aesthetics of French classicism. French classicism begins from the
classical maxim that the beautiful is the true. Nicolas Boileau writes
in his influential didactic poem, *The Art of Poetry* (1674),
in which he lays down rules for good versification within different
genres, that "Nothing is beautiful but the true, the true alone
is lovable." In the period the true is conceived of as an
objective rational order. According to the classical conception of art
that dominates in the period, art *imitates* nature, though not
nature as given in disordered experience, but the *ideal*
nature, the ideal in which we can discern and enjoy "unity in
multiplicity." In French classicism, aesthetics is very much
under the influence of, and indeed modeled on, systematic, rigorous
theoretical science of nature. Just as in Descartes' model of
science, where knowledge of all particulars depends on prior knowledge
of the principle from which the particulars are deduced, so also in
the aesthetics of French classicism, the demand is for systematization
under a single, universal principle. The subjection of artistic
phenomena to universal rules and principles is expressed, for example,
in the title of Charles Batteaux's main work, *The Fine Arts
Reduced to a Single Principle* (1746), as well as in
Boileau's rules for good versification.



In Germany in the eighteenth century, Christian Wolff's
systematic rationalist metaphysics forms the basis for much of the
reflection on aesthetics, though sometimes as a set of doctrines to be
argued against. Wolff affirms the classical dictum that beauty is
truth; beauty is truth perceived through the feeling of pleasure.
Wolff understands beauty to consist in the perfection in things, which
he understands in turn to consist in a harmony or order of a manifold.
We judge something beautiful through a feeling of pleasure when we
sense in it this harmony or perfection. Beauty is, for Wolff, the
sensitive cognition of perfection. Thus, for Wolff, beauty corresponds
to objective features of the world, but judgments of beauty are
relative to us also, insofar as they are based on the human faculty of
sensibility.


### 3.2 Empiricism and Subjectivism



Though philosophical rationalism forms the basis of aesthetics in the
early Enlightenment in France and Germany, thinkers in the empiricist
tradition in England and Scotland introduce many of the salient themes
of Enlightenment aesthetics. In particular, with the rise of
empiricism and subjectivism in this domain, attention shifts to the
ground and nature of the subject's experience of beauty, the
subject's aesthetic response. Lord Shaftesbury, though not
himself an empiricist or subjectivist in aesthetics, makes significant
contributions to this development. Shaftesbury re-iterates the
classical equation, "all beauty is truth," but the truth
that beauty is for Shaftesbury is not an objective rational order that
could also be known conceptually. Though beauty is, for Shaftesbury, a
kind of harmony that is independent of the human mind, under the
influence of Plotinus, he understands the human being's
immediate intuition of the beautiful as a kind of participation in the
original harmony. Shaftesbury focuses attention on the nature of the
subject's response to beauty, as elevating the person, also
morally. He maintains that aesthetic response consists in a
*disinterested* unegoistic pleasure; the discovery of this
capacity for disinterested pleasure in harmony shows the way for the
development of his ethics that has a similar grounding. And, in fact,
in seeing aesthetic response as elevating oneself above
self-interested pursuits, through cultivating one's receptivity
to disinterested pleasure, Shaftesbury ties tightly together
aesthetics and ethics, morality and beauty, and in that respect also
contributes to a trend of the period. Also, in placing the emphasis on
the subject's response to beauty, rather than on the objective
characteristics of the beautiful, Shaftesbury makes aesthetics belong
to the general Enlightenment interest in human nature. Thinkers of the
period find in our receptivity to beauty a key both to understanding
both distinctively human nature and its perfection.



Francis Hutcheson follows Shaftesbury in his emphasis on the
subject's aesthetic response, on the distinctive sort of
pleasure that the beautiful elicits in us. Partly because the
Neo-Platonic influence, so pronounced in Shaftesbury's
aesthetics, is washed out of Hutcheson's, to be replaced by a
more thorough-going empiricism, Hutcheson understands this distinctive
aesthetic pleasure as more akin to a secondary quality. Thus,
Hutcheson's aesthetic work raises the prominent question whether
"beauty" refers to something objective at all or whether
beauty is "nothing more" than a human idea or experience.
As in the domain of Enlightenment ethics, so with Enlightenment
aesthetics too, the step from Shaftesbury to Hutcheson marks a step
toward subjectivism. Hutcheson writes in one of his *Two
Treatises*, his *Inquiry Concerning Beauty, Order, Harmony,
Design* (1725) that "the word 'beauty' is taken
for the *idea raised in us*, and a *sense* of beauty for
*our power of receiving this idea*" (Section I, Article
IX). However, though Hutcheson understands beauty to be an idea in us,
he takes this idea to be "excited" or
"occasioned" in us by distinctive objective qualities, in
particular by objects that display "*uniformity amidst
variety*" (ibid., Section II, Article III). In the very
title of Hutcheson's work above, we see the importance of the
classical ideas of (rational) order and harmony in Hutcheson's
aesthetic theory, even as he sets the tenor for much Enlightenment
discussion of aesthetics through placing the emphasis on the
subjective idea and aesthetic response.



David Hume's famous essay on "the standard of taste"
raises and addresses the epistemological problem raised by
subjectivism in aesthetics. If beauty is an idea in us, rather than a
feature of objects independent of us, then how do we understand the
possibility of correctness and incorrectness - how do we
understand the possibility of standards of judgment - in this
domain? The problem is posed more clearly for Hume because he
intensifies Hutcheson's subjectivism. He writes in the
*Treatise* that "pleasure and pain....are not only
necessary attendants of beauty and deformity, but constitute their
very essence" (*Treatise*, Book II, part I, section
viii). But if a judgment of taste is based on, or expresses,
subjective sentiments, how can it be incorrect? In his response to
this question, Hume accounts for the expectation of agreement in
judgments of taste by appealing to the fact that we share a common
human nature, and he accounts for 'objectivity' or
expertise in judgments of taste, within the context of his
subjectivism, by appealing to the normative responses of well-placed
observers. Both of these points (the commonality of human nature and
the securing of 'objectivity' in judgments based on
sentiments by appeal to the normative responses of appropriately
placed observers) are typical of the period more generally, and
especially of the strong empiricist strain in the Enlightenment. Hume
develops the empiricist line in aesthetics to the point where little
remains of the classical emphasis on the order or harmony or truth
that is, according to the French classicists, apprehended and
appreciated in our aesthetic responses to the beautiful, and thus,
according to the classicists, the ground of aesthetic responses.


### 3.3 Late Enlightenment Aesthetics



Immanuel Kant faces squarely the problem of the normativity of
judgments of taste. Influenced by Hutcheson and the British empiricist
tradition in general, Kant understands judgments of taste to be
founded on a distinctive sort of feeling, a *disinterested*
pleasure. In taking judgments of taste to be subjective (they are
founded on the subject's feeling of pleasure) and non-cognitive
(such judgments do not subsume representations under concepts and thus
do not ascribe properties to objects), Kant breaks with the German
rationalist school. However Kant continues to maintain that judgments
of beauty are like cognitive judgments in making a legitimate claim to
universal agreement - in contrast to judgments of the agreeable.
The question is how to vindicate the legitimacy of this demand. Kant
argues that the distinctive pleasure underlying judgments of taste is
the experience of the harmony of the faculties of the imagination and
the understanding, a harmony that arises through their "free
play" in the process of cognizing objects on the basis of given
sensible intuition. The harmony is "free" in an experience
of beauty in the sense that it is not forced by rules of the
understanding, as is the agreement among the faculties in acts of
cognition. The order and harmony that we experience in the face of the
beautiful is subjective, according to Kant; but it is at the same time
universal and normative, by virtue of its relation to the conditions
of human cognition.



The emphasis Kant places on the role of the activity of the
imagination in aesthetic pleasure and discernment typifies a trend in
Enlightenment thought. Whereas early in the Enlightenment, in French
classicism, and to some extent in Christian Wolff and other figures of
German rationalism, the emphasis is on the more-or-less static
rational order and proportion and on rigid universal rules or laws of
reason, the trend during the development of Enlightenment aesthetics
is toward emphasis on the *play* of the imagination and its
fecundity in generating associations.



Denis Diderot is an important and influential author on aesthetics. He
wrote the entry "On the Origin and Nature of the
Beautiful" for the *Encyclopedia* (1752). Like Lessing in
Germany, Diderot not only philosophized about art and beauty, but also
wrote plays and influential art criticism. Diderot is strongly
influenced in his writings on aesthetics by the empiricism in England
and Scotland, but his writing is not limited to that standpoint.
Diderot repeats the classical dictum that art should imitate nature,
but, whereas, for French classicists, the nature that art should
imitate is *ideal* nature - a static, universal rational
order - for Diderot, nature is dynamic and productive. For
Diderot, the nature the artist ought to imitate is the *real*
nature we experience, warts and all (as it were). The particularism
and realism of Diderot's aesthetics is based on a critique of
the standpoint of French classicism (see Cassirer 1935, p. 295f.).
This critique exposes the artistic rules represented by French
classicists as universal rules of reason as nothing more than
*conventions* marking what is considered *proper* within
a certain tradition. In other words, the prescriptions within the
French classical tradition are *artificial*, not
*natural*, and constitute fetters to artistic genius. Diderot
takes liberation from such fetters to come from turning to the task of
observing and imitating *actual nature*. Diderot's
emphasis on the primeval productive power and abundance of nature in
his aesthetic writings contributes to the trend toward focus on
artistic creation and expression (as opposed to artistic appreciation
and discernment) that is a characteristic of the late Enlightenment
and the transition to Romanticism.



Lessing's aesthetic writings play an important role in elevating
the aesthetic category of expressiveness. In his famous
*Laocoon: An Essay on the Limits of Painting and Poetry*
(1766), Lessing argues, by comparing the famous Greek statue with the
representation of Laocoon's suffering in Virgil's
poetry, that the aims of poetry and of the visual arts are not
identical; he argues that the aim of poetry is not beauty, but
expression. In elevating the aesthetic category of expressiveness,
Lessing challenges the notion that all art is imitation of nature. His
argument also challenges the notion that all the various arts can be
deduced from a single principle. Lessing's argument in
*Laocoon* supports the contrary thesis that the distinct
arts have distinct aims and methods, and that each should be
understood on its own terms, not in terms of an abstract general
principle from which all arts are to be deduced. For some, especially
for critics of the Enlightenment, in this point Lessing is already
beyond the Enlightenment. Certainly it is true that the emphasis on
the individual or particular, over against the universal, which one
finds in other late Enlightenment thinkers, is in tension with
Enlightenment tenets. Herder (following Hamann to some extent) argues
that each individual art *object* has to be understood in its
own terms, as a totality complete unto itself. With Herder's
stark emphasis on individuality in aesthetics, over against
universality, the supplanting of the Enlightenment with Romanticism
and Historicism is well advanced. But, according to the point of view
taken in this entry, the conception of the Enlightenment according to
which it is distinguished by its prioritization of the order of
abstract, universal laws and principles, over against concrete
particulars and the differences amongst them, is too narrow; it fails
to account for much of the characteristic richness in the thought of
the period. Indeed aesthetics itself, as a discipline, which, as
noted, is founded in the Enlightenment by the German rationalist,
Alexander Baumgarten, owes its existence to the tendency in the
Enlightenment to search for and discover distinct laws for distinct
kinds of phenomena (as opposed to insisting that all phenomena be made
intelligible through the same set of general laws and principles).
Baumgarten founds aesthetics as a 'science' through the
attempt to establish the sensible domain as cognizable in a way
different from that which prevails in metaphysics. Aesthetics in
Germany in the eighteenth century, from Wolff to Herder, both typifies
many of the trends of the Enlightenment and marks the field where the
Enlightenment yields to competing worldviews.