The Enlightenment was a broad intellectual tendency, spanning philosophy, literature, language, art, religion and political theory, which lasted from around 1680 until the end of the eighteenth century. Conventionally, the Enlightenment has been called the “age of reason,” though this designation is now regarded as somewhat reductive since it fails to comprehend the various intellectual trends of the period. The Enlightenment thinkers were by no means uniform in their outlooks, but in general they saw themselves as initiating an era of humanitarian, intellectual and social progress, underlain by the increasing ability of human reason to subjugate analytically both the external world of nature and the human self. They viewed it as their mission to rid human thought and institutions of irrational prejudice and superstition, as well as to foster a society free of feudal caprice, political absolutism and religious intolerance, and where human beings could realize their potential through making moral and political choices on the foundations of rationality and freedom. In political and economic terms, Enlightenment thought was integral to the rise of liberalism and the ascendancy to power of the bourgeois class through the French Revolution of 1789 and subsequent revolutions throughout Europe. Indeed, it should be remembered that reason was not merely a neutral knowledge-seeking human faculty given prominence by philosophy; the reverberations of reason as a way of life, as a fundamental disposition toward the world, had their foundations in the economic sphere, underlying newer, rational attitudes toward banking, investment, trade and manufacture, and harboring profound implications for the status of science and technology.
These images of the Enlightenment, and in particular the power and objectivity of reason, have been challenged from many directions: initially, by certain figures usually included within the orbit of Enlightenment thought, such as Rousseau who stressed the importance of emotion and instinct, and Hume whose scepticism embraced even the abilities of reason; by Theodor Adorno, Max Horkehimer and many others such as Roland Barthes, who have developed the critique, originally advanced by Marx and Engels, of the “empire of reason” as a foundation of bourgeois ideology; by an alternative, heterological tradition of philosophy running from Schopenhauer, Nietzsche, and Bergson to Derrida which has emphasized the intrinsic connection of reason with ideological and pragmatic interests and physical survival; by the psychoanalytic traditions generated from Freud and Jung, which have stressed how small a component of human behavior is accounted for by reason; by Feminisms which have viewed reason as a predominant factor in male constructions of the world and as internally constrained by the complex claims of the body; and by various forms of poststructuralist and postcolonial theory, which have situated reason as a peculiarly European phenomenon intrinsically tied to class interests and the projects of imperial hegemony. At its very heart, reason was from the beginning ideologically orientated, on many levels. Hence, all of these movements and tendencies have challenged the claims of reason to neutrality, impartiality objectivity and universality.
Notwithstanding these critiques, which have variously exerted force since the early twentieth century, the main streams of the Enlightenment continue to have a profound effect on our world. Much Enlightenment thought was underlain by a new scientific vision of the universe inspired by the work of the English mathematician Sir Isaac Newton (1642-1727): this conception of a mechanical universe ordered by laws which were scientifically ascertainable eventually displaced the view of the universe as ordered and historically directed by a benevolent Divine Providence. The very concept of reason issued a profound challenge to centuries’ old traditions of thought and institutional practice. Reliance on reason was in itself nothing new; the classical philosophers such as Plato and Aristotle had urged reason as the faculty through which we could gain access to truths which were universal and certain. Mediaeval Christian philosophy acknowledged that reason was a necessary component of a proper spiritual disposition, but it was only one element and needed to be balanced by faith and revelation. In other words, reason was constrained within a broader pattern of human faculties and its limitations were stressed: reason alone could not gain access to God or salvation, nor could it probe the ultimate mysteries of the universe. What was novel to the Enlightenment was its insistence on reason as the primary faculty through which we could acquire knowledge, and on its potentially limitless application. The findings of reason need no longer be constrained by the requirements of faith or the dictates of divine revelation. More than this, the exaltation of reason, of man’s individual capacity for reasoning, effectively undermined reliance on any form of authority, whether it be the authority of the Church, the State, of tradition, convention or of any powerful individual. This way of thinking is particularly marked in modern democracies even today: as Alexis de Tocqueville noted about America, people in general prefer to rely on their own insight (however uninformed) rather than submit to the authority or testimony of others, even of experts.
Three seminal precursors of Enlightenment thought were the English thinker Francis Bacon (1561-1626), the French rationalist philosopher Rene Descartes (1596-1650), and the Dutch rationalist thinker Benedict (or Baruch) Spinoza (1632-1677). Bacon’s major philosophical works were The Advancement of Learning (1605) and The New Organon (1620), where he formulated the method of induction whereby we generalize on the basis of actual observation of a number of particular occurrences. He proposed that induction, as the method of modern science, was a more effective path to knowledge than the Mediaeval reliance on deduction and a priori reasoning, whose premises were handed down by the authority of tradition. In The New Organon Bacon insisted that knowledge can arise only from actual observation of nature; the elements of logic, such as the syllogism, which underlie much Mediaeval philosophy, he says, may form a coherent structure within itself but is not necessarily tied to actual fact. A syllogism, for example, could be valid inasmuch as its propositions flow logically, but these propositions could nonetheless be untrue. The only secure way to arrive at knowledge, then, is by a “true induction,” whereby reason is applied to observed facts; only in this way can ideas and axioms be generated.
Even though certain systems of thought have commanded assent for centuries, Bacon asserts that we must begin anew from this alternative foundation. Up until now, he warns, the human mind has been misled by what he calls “idols” or false notions. He divides these idols into four classes. The first type are “Idols of the Tribe,” which refer to the distorted impressions of nature caused by the deficiencies of sense and understanding common to all human beings; the next are “Idols of the Cave”: each man, he says, has a private cave or den, through which or from which he sees the world. The cave is a metaphor for the peculiarity of an individual’s nature and upbringing: his view of the world will be refracted and distorted by his subjective experiences; the third kind of idols are those of the “marketplace,” again a metaphor for “the commerce and consort of men”: when men enter into social bonds, a social discourse is created which panders to the “vulgar” in its vagueness and intellectual insufficiency. Finally, there are “Idols of the Theatre”: these are the systems of philosophers and learned men which are “merely stage plays” because they represent “worlds of their own creation” rather than the actual world .1 The upholders of these previous systems urge us to view the world through those fictions rather than experiencing it directly for ourselves.
Rene Descartes (1596-1650) is often called the “father” of modern philosophy. Like Bacon, Descartes challenged th basic principles of Mediaeval philosophy. In his Discourse on Method he began his thinking in a sceptical mode, doubting all things, including his own senses, understanding and the reality of the external world, until he could find a secure and certain foundation on which to build his own system of thought. Descartes resolved to “reject as absolutely false everything as to which I could imagine the least ground of doubt” in order to see if any kind of certain knowledge remained. He first doubted the deliverances of our sense, since they often deceive us; he then doubted the process of reasoning; he imagined that the entire world might be a delusion. But, in assuming everything to be false, Descartes concluded: _it was absolutely essential that the _I_ who thought this should be somewhat [something], and remarking that this truth _ I think, therefore I am_
was so certain and so assured…I came to the conclusion that I could receive it…as the first principle of the Philosophy for which I was seeking. Descartes proceeded to identify his essential nature or self with the process of thinking, calling himself a “thinking being,” independent of any place or any material circumstances. In this way, he made his famous dualism or distinction between the mind and the body. The mind is a thinking substance, whereas the body belongs to the world of space, time and material extension. In this way, Descartes perpetuated a mechanistic view of the world. Descartes inferred from his earlier process of doubt that he could take it as a general rule that the things which we conceive very _clearly and very distinctly_ are all true.”2 Descartes took mathematics as his model of knowledge given that its ideas were clear and distinct and that its truths were certain.
The third seminal figure, Spinoza, was a Jew born in Amsterdam, who had studied Descartes’ works closely. His own rationalist and unorthodox views led to his expulsion from the Jewish community in 1656 for heresy. He also offended Christian theologians by his unorthodox views of the Bible. Like Descartes, he believed in the primacy of deduction and in a mechanistic view of the universe; however, he did not adopt Cartesian dualism, arguing instead that the universe is composed of a single substance, which he viewed as God, and which is refracted differently in the attributes of mind and matter. In his major work, the Ethics (1677) he urged that the highest good consists in the rational mastery over one’s passions and ultimately in the acceptance of the the order and harmony in nature, which is an expression of the divine nature. Subsequent Enlightenment thinkers such as John Locke (1632-1704) and David Hume (1711-1776) in Britain, Voltaire (1694-1778), Diderot and d=Alembert in France, as well as Gotthold Lessing (1729-1781) in Germany, encouraged more sceptical, rational and tolerant approaches to religion. The most common approach was ADeism,@ which saw divine laws as natural and rational, and dismissed all superstition, miracles and sacraments.
Bacon and Descartes represent what were to become two important strands of Enlightenment thought, empiricism and rationalism respectively. Bacon’s empiricism placed emphasis on our experience and observation of the world; Descartes stressed the use of our reason to arrive at clear and distinct notions of the world. Another stream of Enlightenment thought was materialism, which marks the thought of the thinkers just discussed but is most fully represented by Thomas Hobbes (1588-1679). Hobbes expounded a materialistic view of even the mind, regarding sensation as caused by the impact and interaction of small particles.
In political terms, the Enlightenment produced several blueprints of what might be an ideal state. Several Enlightenment philosophers drew up a theory of the “social contract,” or the contract that might be agreed upon by citizens of a state so that social life would be governed by laws and that the ruler’s power and his relation to his subjects in terms of rights and duties would be defined. Many of these thinkers postulate what men would be like in a state of nature, prior to the formation of a social contract. Hobbes’ view of this state, as expressed in his Leviathan (1651) is bleak: he suggests that, without any binding laws or contract, men would be in a perpetual state of war. His reasoning is that nature has basically made men equal; from this equality proceeds “diffidence” (by which Hobbes means hostility or aggressiveness), since men, whose principal purpose is self-conservation, would be competing for the same things. Eventually, war would result, since in order to secure themselves as fully as possible, men would attempt to master as many other people as they could. A third cause of quarrel would be the desire for glory and reputation. In this condition of war, says Hobbes, there would be no trade or industry, no culture, no arts, letters or science. There would be merely “continual fear, and danger of violent death; and the life of man, solitary, poor, nasty, brutish, and short.” In this state of nature, there would be no rules, no morality, no justice and no law: these institutions, says Hobbes, belong to man as he lives in society, not in solitude. Even after a social contract is established between persons of a given state, says Hobbes, one state will nonetheless be in a posture of war against other states; this condition, however, unlike that of a war of individuals, may actually promote industry and happiness.
One of the major empiricist thinkers of the Enlightenment, and the most important philosopher in the formulation of political liberalism was John Locke (1632-1704), whose most influential works were An Essay Concerning Human Understanding and Two Treatises on Civil Government, both published in 1690. In the Essay Locke denied Descartes’ view that the mind has “innate ideas,” or ideas that it is simply born with. Rather, the mind is initially a tabula rasa or blank slate upon which our experience of the world is written.3 Locke argues that all our ideas come from experience, either through sensation or reflection. We receive distinct ideas of the objects in the external world through our senses, such as the ideas of yellow, white, hard, cold or soft; we also receive ideas through reflection on the internal operation of our own minds; these ideas include perception, thinking, doubting, reasoning and believing . These two operations, he says, are “the fountains of knowledge” and there is no other source of knowledge or ideas (Essay, 89-90, 348). Where Locke does agree with Descartes is in his insistence on clear and distinct ideas; as we shall see, like some modern philosophers of language, Locke blamed the misuse or abuse of language for many of our misconceptions about the world, and proposed that language should be made more precise.
The Scottish philosopher David Hume (1711-1776) developed some of Locke’s empiricist notions toward more radical, sceptical, conclusions. Where Locke had urged that our minds know the external world through ideas, Hume argued that we know only ideas, not the external world itself. We can know external objects only by the “perceptions they occasion,” and we can infer their existence only from “the coherence of our perceptions,” whether they indeed are real or merely “illusions of the senses.”4 In fact, Locke himself acknowledged that even simple ideas, which were the very core of experience, cannot be proved to correspond with reality, and he admitted that the real essence of things is unknowable (Essay, 271-273, 287, 303). Both Locke and Hume rejected the Aristotelian concept of “substance” as the underlying substratum of reality. Hume develops the scepticism implicit in Locke’s rejection of substance: there are no essences actually in the world, whether we are talking of external objects such as a table, or human identity, or moral concepts such as goodness. All of these are ultimately constructions of our minds, informed largely by custom and habit. Indeed, in Hume’s view, even the human self was not a fixed datum but a construction through a “succession of perceptions” (THN, 135). Hence the very notion of human identity is called into question by Hume. Moreover, in Hume’s eyes, the law of causality, on which the entire thrust of modern science was based and which was hailed as the “ultimate principle” of the universe, has merely a conventional validity, based on nothing more than the authority of custom (THN, 316). What we perceive in the world is not the operation of causality but mere “constant conjunction,'” in other words, our own long habit of associating two phenomena.
In France, the main figures of the Enlightenment were Voltaire (1694-1778), Denis Diderot and Jean d’Alembert. Perhaps more than anyone else, Voltaire popularised the ideas of Newton and Locke. As a young man, he was imprisoned in the Bastille for his satiric verses on the aristocracy, and later exiled in England. His numerous works included the Philosophical Dictiionary (1764) and a ficional philosophical tale Candide (1759) in which he promulgated the necessity of reason and experience, and the notion that the world is governed by natural laws. In Candide he mocked the optimism, determinism and rationalism of the German philosopher Gottfried Leibniz who believed in a pre-established harmony in the world, lampooning the latter’s position in the phrase “Everything is for the best in this best of all possible worlds.” The implication is that abstract reason of itself does not comprehend the infinite variety of human situations and human deficiencies. In this sense, reason is held up as a kind of comforting fiction,pandering to the human need for order. Voltaire satirizes the “rational” justifications for war, the intolerance of religions, the institutions of inequality, the search for a Utopia, the greed which undermines human contentment, the gullibility of the masses, and the strength of human self-deception; one of the two stark lessons to emerge is the need to experience the world directly: “to know the world one must travel,” concludes Candide. The only lesson is the need to work, in order to stave off the “three great evils, boredom, vice and poverty.” In general, Voltaire championed liberty and freedom of speech, though his sympathies did not extend to the common man. The other French Enlightenment thinkers included the rationalists Diderot and d’Alembert, who were the leading members of the group which produced the Encyclopaedia, a compendium of the latest scientific and philosophical knowledge. In Germany, the tendencies of the Enlightenment were expressed by Gotthold Lessing (1729-1781) and Moses Mendelssohn (1729-1786) who both propounded philosophies of religious tolerance.
Certain Enlightenment philosophies had a formative influence on the ideals behind the French Revolution. These included Locke=s Second Treatise of Civil Government (1690) which justified the new political system in England that prevailed after the 1688 revolution. Locke condemned despotic monarchy and the absolute sovereignty of parliaments, affirming that the people had a right to resist tyranny. Voltaire advocated an enlightened monarchy or republic governed by the bourgeois classes. Baron de Montesquieu (1689-1755) also influenced the first stage of the French Revolution, advancing a liberal theory based on a separation of executive, legislative and judicial powers. Jean Jacques Rousseau (1712-1778) exerted a powerful impact on the second stage of the Revolution through his theories of democracy, egalitarianism and the evils of private property, as advocated in his Social Contract and Discourse on the Origin of Inequality. However, in some ways, Rousseau hardly belongs to the main trends of rationalist Enlightenment thought. Significantly, he is often hailed as the father of Romanticism on account of his exaltation of the state of nature over civilization, and of the emotions and instincts over reason and conventional learning.
In general, however, the major tendencies of Enlightenment philosophy were towards rationalism, empiricism, pragmatism and utilitarianism; these tendencies formed the core of liberal-bourgeois thought. The main philosophical assumptions behind this tradition of thought were: that the world is composed of particular things which are distinct and separate from one another (philosophical pluralism); that consciousness (the human self) and the world are mutually distinct, and there is an external reality independent of our minds; and that general ideas are formed from the association and abstraction of particular ones (in other words, general ideas are constructions of our minds and are not found in the world). It is these assumptions that underlay the other trends of Enlightenment thinking: that the world is a machine, subject to laws; that human society is an aggregate of atomistic or separate individuals; that the individual is an autonomous and free rational agent; that reliance on reason and experience or observation will enable us to understand the world, the human self, and enable historical progress in humanitarian, moral, religious and political terms.