The Age of Enlightenment refers to the 18th century in European philosophy, and is often thought of as part of a larger period which includes the Age of Reason. The term also more specifically refers to a historical intellectual movement, “The Enlightenment.” This movement advocated rationality as a means to establish an authoritative system of ethics, aesthetics, and knowledge. The intellectual leaders of this movement regarded themselves as courageous and elite, and regarded their purpose as leading the world toward progress and out of a long period of doubtful tradition, full of irrationality, superstition, and tyranny (which they believed began during a historical period they called the “Dark Ages”). This movement also provided a framework for the American and French Revolutions, the Latin American independence movement, and the Polish Constitution of May 3, and also led to the rise of capitalism and the birth of socialism. It is matched by the high baroque and classical eras in music, and the neo-classical period in the arts, and receives contemporary application in the unity of science movement which includes logical positivism.
Another important movement in 18th century philosophy, which was closely related to it, was characterized by a focus on belief and piety. Some of its proponents attempted to use rationalism to demonstrate the existence of a supreme being. In this period, piety and belief were integral parts in the exploration of natural philosophy and ethics in addition to political theories of the age. However, prominent Enlightenment philosophers such as Voltaire, Jean-Jacques Rousseau, and David Hume questioned and attacked the existing institutions of both Church and State.
The 18th century also saw a continued rise of empirical philosophical ideas, and their application to political economy, government and sciences such as physics, chemistry and biology.
According to scholarly opinion, the Enlightenment was preceded by the Age of Reason (if thought of as a short period) or by the Renaissance and the Reformation (if thought of as a long period). It was followed by Romanticism.
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History of Enlightenment philosophy
The boundaries of the Enlightenment cover much of the 17th century as well, though others term the previous era “The Age of Reason.” For the present purposes, these two eras are split; however, it is equally acceptable to think of them conjoined as one long period.
Throughout the 1500s and half of the 1600s, Europe was ravaged by religious wars. When the political situation stabilized after the Peace of Westphalia and at the end of the English Civil War, there was an upheaval which overturned the notions of mysticism and faith in individual revelation as the primary source of knowledge and wisdom—perceived to have been a driving force for instability. Instead, (according to those that split the two periods), the Age of Reason sought to establish axiomatic philosophy and absolutism as the foundations for knowledge and stability. Epistemology, in the writings of Michel de Montaigne and René Descartes, was based on extreme skepticism, and inquiry into the nature of “knowledge.” This goal in the Age of Reason, which was built on self-evident axioms, reached its height with Baruch (Benedictus de) Spinoza’s Ethics, which expounded a pantheistic view of the universe where God and Nature were one. This idea became central to the Enlightenment from Newton through to Jefferson.
The Enlightenment was, in many ways, influenced by the ideas of Pascal, Leibniz, Galileo and other philosophers of the previous period. For instance, E. Cassirer has asserted that Leibniz’s treatise On Wisdom “. . . identified the central concept of the Enlightenment and sketched its theoretical program” (Cassirer 1979: 121–123). There was a wave of change across European thinking at this time, which is also exemplified by the natural philosophy of Sir Isaac Newton. The ideas of Newton, which combined the mathematics of axiomatic proof with the mechanics of physical observation, resulted in a coherent system of verifiable predictions and set the tone for much of what would follow in the century after the publication of his Philosophiae Naturalis Principia Mathematica.
But Newton was not alone in the systematic revolution in thinking; he was merely the most visible and famous example. The idea of uniform laws for natural phenomena mirrored the greater systematization in a variety of studies. If the previous era was the age of reasoning from first principles, Enlightenment thinkers saw themselves as looking into the mind of God by studying creation and deducing the basic truths of the world. This view may seem overreaching to some in the present-day, where belief is that human beings apprehend a truth that is more provisional, but in that era it was a powerful notion which turned on its head the previous basic notions of the sources of legitimacy.
For those that divide the “Age of Reason” from the “Enlightenment,” the precipitating figure of Newton offers a specific example of the importance of the difference, because he took empirically observed and codified facts, such as Kepler’s planetary motion, and the “opticks” which had explained lenses, and began to create an underlying theory of how they functioned. This shift united the pure empiricism of Renaissance figures such as Lord Francis Bacon with the axiomatic approach of Descartes. The belief in a comprehensible world, under an orderly Christian God, provided much of the impetus for philosophical inquiry. On the one hand, religious philosophy focused on the importance of piety, and the majesty and mystery of God’s ultimate nature; on the other hand, ideas such as Deism stressed that the world was accessible to the faculty of human reason, and that the “laws” which governed its behavior were understandable. The notion of a “clockwork god” or “god the watchmaker” became prevalent, as many in the time period saw new and increasingly sophisticated machines as a powerful metaphor for a seemingly orderly universe.
Central to this philosophical tradition was the belief in objective truth independent of the observer, expressible in rigorous human terms. The quest for the expression of this truth would lead to a series of philosophical works which alternately advanced the scepticist position that it is impossible to know reality in the realm of experience, and the idealist position that the mind was capable of encompassing a reality which lies outside of its direct experience. The relationship between being and perception would be explored by George Berkeley and David Hume, and would eventually be the problem that occupied much of Immanuel Kant’s philosophy.
The focus on law, involving the separation of rules from the particulars of behavior or experience, was essential to the rise of a philosophy which had a much stronger concept of the individual; according to this concept, his rights were based on ideals other than ancient traditions, or tenures, and instead reflected the intrinsic quality of a person as defined by the philosophers of the age. John Locke wrote his Two Treatises on Government to argue that property was not a family right by tenure, but an individual right brought on by mixing labour with the object in question, and securing it from other use. This focus on process and procedure would be honoured, at times, in the breach, as England’s own “Star Chamber” court would attest to. However, once the concept established that there were natural rights, as there were natural laws, it became the basis for the exploration of what we would now call economics, and political philosophy.
In his famous 1784 essay “What Is Enlightenment?”, Immanuel Kant defined it as follows:
Enlightenment is man’s leaving his self-caused immaturity. Immaturity is the incapacity to use one’s intelligence without the guidance of another. Such immaturity is self-caused if it is not caused by lack of intelligence, but by lack of determination and courage to use one’s intelligence without being guided by another. Sapere Aude! [Dare to know!] Have the courage to use your own intelligence! is therefore the motto of the enlightenment.
The Enlightenment began then, from the belief in a rational, orderly and comprehensible universe—then proceeded, in stages, to form a rational and orderly organization of knowledge and the state, such as what is found in the idea of Deism. This began from the assertion that law governed both heavenly and human affairs, and that law invested the king with his power, rather than the king’s power giving force to law. The conception of law as a relationship between individuals, rather than families, came to the fore, and with it the increasing focus on individual liberty as a fundamental right of man, given by “Nature and Nature’s God,” which, in the ideal state, would encompass as many people as possible. Thus The Enlightenment extolled the ideals of liberty, property and rationality which are still recognizable as the basis for most political philosophies even in the present era; that is, of a free individual being mostly free within the dominion of the state whose role is to provide stability to those natural laws.
The “long” Enlightenment is seen as beginning the Renaissance drive for humanism and empiricism. It was built on the growing natural philosophy that espoused the application of algebra to the study of nature, and the discoveries brought about by the invention of the microscope and the telescope. There was also an increasingly complex philosophy of the role of the state and its relationship to the individual. The turbulence of religious wars had brought about a desire for balance, order, and unity.
Two good examples which help illustrate why many historians split the Age of Reason from the Enlightenment are the works of Thomas Hobbes and John Locke. Hobbes, whose ideas are a product of the age of reason, systematically pursues and categorizes human emotion, and argues for the need of a rigid system to hold back the chaos of nature in his work Leviathan. While John Locke is clearly an intellectual descendant of Hobbes, for him the state of nature is the source of all rights and unity, and the state’s role is to protect, and not to hold back, the state of nature. This fundamental shift, from a rather chaotic and dark view of nature, to a fundamentally orderly view, is an important aspect of the Enlightenment.
A second wave of Enlightenment thinking began in France with the Encyclopédistes. The premise of their enterprise was that there is a moral architecture to knowledge. Mixing personal comment with the attempt to codify knowledge, Denis Diderot and Jean le Rond d’Alembert sought liberation for the mind in the ability to grasp knowledge.
The Enlightenment was suffused with two competing strains. One was characterised by an intense spirituality, and faith in religion and the church. In opposition to this, there was a growing streak of anti-clericalism which mocked the perceived distance between the supposed ideals of the church, and the practice of priests. For Voltaire « Écrasez l’infâme! » (“Crush Infamy!”) would be a battle cry for the ideal of a triumphant, rational society.
By the mid-century, what was regarded by many as the pinnacle of purely Enlightenment thinking was being reached with Voltaire—whose combination of wit, insight, and anger made him the most hailed man of letters since Erasmus. Born François Marie Arouet in 1694, he was exiled to England between 1726 and 1729, and there he studied Locke, Newton, and the English Monarchy. Voltaire’s ethos was that “Those who can make you believe absurdities can make you commit atrocities”—that if people believed in what is unreasonable, they will do what is unreasonable.
This point is, perhaps, the central point of contention over the Enlightenment: whether the construction of reason and credibility creates, inherently, as many problems as it deals with. From the perspective of many crucial figures of the Enlightenment, credible reports, viewed through the lens of reason annealed knowledge, empirical observation, and knowledge should be compiled into a source which stood as the authoritative one. The opposing view, which was held with increasing force by the Romantic movement and its adherents, is that this process is inherently corrupted by social convention, and bars truth which is unique, individual and immanent from being expressed.
The Enlightenment balanced then, on the call for “natural” freedom which was good, without a “license” which would, in their view, degenerate. Thus the Age of Enlightenment sought reform of the Monarchy by laws which were in the best interest of its subjects, and the “enlightened” ordering of society. The idea of enlightened ordering was reflected in the sciences by, for example, Carolus Linnaeus’ categorization of biology.
In mid-century Germany, the idea of philosophy as a critical discipline began with the work of Gotthold Ephraim Lessing and Johann Gottfried Herder. Both argued that formal unities that underlie language and structure hold deeper meaning than a surface reading, and that philosophy could be a tool for improving the virtue, political and personal, of the individual. This strain of thinking would influence Kant’s critiques, as well as subsequent philosophers seeking an apparatus to examine works, beliefs and social organization, and it is particularly notable in the history of later German philosophy.
These ideas became volatile when it reached the point where the idea that natural freedom was more self-ordering than hierarchy, since hierarchy was the social reality. As that social reality repeatedly disappointed the fundamentally optimistic ideal that reform could end disasters, there became a progressively more strident naturalism which would, eventually, lead to the Romantic movement.
Thinkers of the last wave of the Enlightenment—Jean-Jacques Rousseau and Immanuel Kant as well as Adam Smith, Thomas Jefferson and the young Johann Wolfgang von Goethe adopted the increasingly used biological metaphor of self-organization and evolutionary forces. This represented the impending end of the Enlightenment: which believed that nature, while basically good, was not basically self-ordering—see Voltaire’s Candide for an example of why not. Instead, it had to be ordered with reasoning and maturity. The impending Romantic view saw the universe as self-ordering, and that chaos was, in a real sense, the result of excesses of rational impositions on an organic world.
This boundary would produce political results: with increasing force in the 1750s there would be attempts in England, Austria, Prussia, Poland and France to “rationalize” the monarchical system and its laws. When this failed to end wars, there was an increasing drive for revolution or dramatic alteration. The Enlightenment idea of rationality as a guiding force for government found its way to the heart of the American Declaration of Independence, and the Jacobin program of the French Revolution, as well as the American Constitution of 1787 and the Polish Constitution of May 3, 1791.
The French Revolution, in particular, represented the Enlightenment philosophy through a violent and messianic lens, particularly during the brief period of Jacobin dictatorship. The desire for rationality in government led to the attempt to end the Roman Catholic Church, and indeed Christianity in France, in addition to changing the calendar, clock, measuring system, monetary system and legal system into something orderly and rational. It also took the ideals of social and economic equality further than any other major state to that time.
But with Napoleon the Enlightenment and its style breathed its last, and longest breath. Napoleon reorganized France into departments, and funded a host of projects. One example of the Enlightenment at work in Revolutionary and Imperial France was the metric system. In a uniform system of weights and measures, based on axiomatic units—the radius of the earth, the weight and thermodynamic properties of water—prices would float based on measurable quantities, rather than price being fixed. It was thought that this would liberate industry from the tyranny of old production laws, and hence from Medieval structure.
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Key conflicts within Enlightenment-period philosophy
As with most periods, the individuals present within the Enlightenment were more aware of their differences than their similarities; within the period there were schools of thought, which saw themselves as widely divergent, even as later perspective has come to consider them similar.
One key conflict is on the role of theology – during the previous period, there had been the splintering of the Catholic Church, not, as with previous schisms, largely along political control of the papacy, but along doctrinal lines between Roman Catholic and Protestant theologies. Consequently, theology itself became a source of partisan debate, with different schools attempting to create rationales for their viewpoints, which then, in turn, became generally used. Thus philosophers such as Spinoza searched for a metaphysics of ethics. This trend would influence pietism and eventually transcendental searches such as those by Immanuel Kant.
Religion was linked to another feature which produced a great deal of Enlightenment thought, namely the rise of the Nation State. In medieval and Renaissance periods, the state was restricted by the need to work through a host of intermediaries. This system existed because of poor communication, where localism thrived in return for loyalty to some central organization. With the improvements in transportation, organization, navigation and finally the influx of gold and silver from trade and conquest, the state began to assume more and more authority and power. The response against this was a series of theories on the purpose of, and limits of state power. The Enlightenment saw both the cementing of absolutism and counter-reaction of limitation advocated by a string of philosophers from John Locke forward, who influenced both Voltaire and Jean-Jacques Rousseau.
Within the period of the Enlightenment, these issues began to be explored in the question of what constituted the proper relationship of the citizen to the monarch or the state. The idea that society is a contract between individual and some larger entity, whether society or state, continued to grow throughout this period. A series of philosophers, including Rousseau, Montesquieu, Hume and ultimately Jefferson advocated this idea. Furthermore, thinkers of this age advocated the idea that nationality had a basis beyond mere preference. Philosophers such as Johann Gottfried von Herder reasserted the idea from Greek antiquity that language had a decisive influence on cognition and thought, and that the meaning of a particular book or text was open to deeper exploration based on deeper connections, an idea now called hermeneutics. The original focus of his scholarship was to delve into the meaning in the Bible and in order to gain a deeper understanding of it. These two concepts – of the contractual nature between the state and the citizen, and the reality of the “nation” beyond that contract, had a decisive influence in the development of liberalism, democracy and constitutional government which followed.
At the same time, the integration of algebraic thinking, acquired from the Islamic world over the previous two centuries, and geometric thinking which had dominated Western mathematics and philosophy since at least Eudoxus, precipitated a scientific and mathematical revolution. Sir Isaac Newton’s greatest claim to prominence came from a systematic application of algebra to geometry, and synthesizing a workable calculus which was applicable to scientific problems. The Enlightenment was a time when the solar system was truly “discovered”: with the accurate calculation of orbits, such as Halley’s comet, the discovery of the first planet since antiquity, Uranus by William Herschel, and the calculation of the mass of the Sun using Newton’s theory of universal gravitation. The effect that this series of discoveries had on both pragmatic commerce and philosophy was momentous. The excitement of creating a new and orderly vision of the world, as well as the need for a philosophy of science which could encompass the new discoveries would show its fundamental influence in both religious and secular ideas. If Newton could order the cosmos with “natural philosophy,” so, many argued, could political philosophy order the body politic.
Within the Enlightenment there were two main theories contending to be the basis of that ordering: “divine right” and “natural law.” It might seem that divine right would yield absolutist ideas, and that natural law would lead to theories of liberty. The writing of Jacques-Benigne Bossuet (1627-1704) set the paradigm for the divine right: that the universe was ordered by a reasonable God, and therefore his representative on earth had the powers of that God. The orderliness of the cosmos was seen as proof of God; therefore it was a proof of the power of monarchy. Natural law, began, not as a reaction against divinity, but instead, as an abstraction: God did not rule arbitrarily, but through natural laws that he enacted on earth. Thomas Hobbes, though an absolutist in government, drew this argument in Leviathan. Once the concept of natural law was invoked, however, it took on a life of its own. If natural law could be used to bolster the position of the monarchy, it could also be used to assert the rights of subjects of that monarch, that if there were natural laws, then there were natural rights associated with them, just as there are rights under man-made laws.
What both theories had in common, however, was the need for an orderly and comprehensible function of government. The “Enlightened Despotism” of, for example, Catherine the Great of Russia is not based on mystical appeals to authority, but on the pragmatic invocation of state power as necessary to hold back chaotic and anarchic warfare and rebellion. Regularization and standardization were seen as good things because they allowed the state to reach its power outwards over the entirety of its domain and because they liberated people from being entangled in endless local custom. Additionally, they expanded the sphere of economic and social activity.
Thus rationalization, standardization and the search for fundamental unities occupied much of the Enlightenment and its arguments over proper methodology and nature of understanding. The culminating efforts of the Enlightenment: for example the economics of Adam Smith, the physical chemistry of Antoine Lavoisier, the idea of evolution pursued by Goethe, the declaration by Jefferson of “inalienable” rights, in the end overshadowed the idea of “divine right” and direct alteration of the world by the hand of God. It was also the basis for overthrowing the idea of a completely rational and comprehensible universe, and led, in turn, to the metaphysics of Hegel and the search for the emotional truth of Romanticism.
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Role of the Enlightenment in later philosophy
This view asserts that the Enlightenment was the point where Europe broke through what historian Peter Gay calls “the sacred circle,” where previous dogma circumscribed thinking. The Enlightenment is held, in this view, to be the source of critical ideas, such as the centrality of freedom, democracy and reason as being the primary values of a society. This view argues that the establishment of a contractual basis of rights would lead to the market mechanism and capitalism, the scientific method, religious and racial tolerance, and the organization of states into self-governing republics through democratic means. In this view, the tendency of the philosophes in particular to apply rationality to every problem is considered to be the essential change. From this point on, thinkers and writers were held to be free to pursue the truth in whatever form, without the threat of sanction for violating established ideas.
With the end of the Second World War and the rise of post-modernity, these same features came to be regarded as liabilities – excessive specialization, failure to heed traditional wisdom or provide for unintended consequences, and the “romanticization” of Enlightenment figures – such as the Founding Fathers of the United States, prompted a backlash against both “Science” and Enlightenment based dogma in general. Philosophers such as Michel Foucault are often understood as arguing that the “age of reason” had to construct a vision of “unreason” as being demonic and subhuman, and therefore evil and befouling, whence by analogy to argue that rationalism in the modern period is, likewise, a construction. In their book The Dialectic of Enlightenment, Max Horkheimer and Theodor Adorno wrote a penetrating critique of what they perceived as the contradictions of Enlightenment thought: Enlightenment was seen as being at once liberatory and, through the domination of instrumental rationality tending towards totalitarianism.
Alternatively, the Enlightenment was used as a powerful symbol to argue for the supremacy of rationalism and rationalization, and therefore any attack on it is connected to despotism and madness, for example in the writings of Gertrude Himmelfarb and Robert Nozick.
This is not to be confused with the role of specific philosophers or individuals from the Enlightenment, but the use of the term in a broad sense by writers in the present of varying points of view.
Precursors of the Enlightenment
Important figures of the Enlightenment era
French Encyclopédistes | Voltaire | Leibniz | Jean-Jacques Rousseau | Condorcet | Helvétius | Fontenelle | Olympe de Gouges | Ignacy Krasicki | Francois Quesney | Benedict Spinoza | Cesare Beccaria | Adam Smith | Isaac Newton | John Wilkes | Antoine Lavoisier | G.L. Buffon | Mikhail Lomonosov | Mikhailo Shcherbatov | Ekaterina Dashkova
Jean le Rond d’Alembert (1717-1783) French. Mathematician and physicist, one of the editors of Encyclopédie
Thomas Abbt (1738-1766) German. Promoted what would later be called Nationalism in Om Tode für’s Vaterland (On dying for one’s nation).
Pierre Bayle (1647-1706) French. Literary critic known for Nouvelles de la république des lettres and Dictionnaire historique et critique.
James Boswell (1740-1795) Scottish. Biographer of Samuel Johnson, helped established the norms for writing Biography in general.
Edmund Burke (1729-1797) Irish. Parliamentarian and political philosopher, best known for pragmatism, considered important to both liberal and conservative thinking.
Denis Diderot (1713-1784) French. Founder of the Encyclopédie, speculated on free will and attachment to material objects, contributed to the theory of literature.
Ignacy Krasicki (1735-1801) Polish. Outstanding poet of the Polish Enlightenment, hailed by contemporaries as “the Prince of Poets.” After the election of Stanis?aw August Poniatowski as king of Poland in 1764, Krasicki became the new King’s confidant and chaplain. He participated in the King’s famous “Thursday dinners” and co-founded the Monitor, the preeminent periodical of the Polish Enlightenment, sponsored by the King. Consecrated Bishop of Warmia in 1766, Krasicki thereby also became an ex-officio Senator of the Polish-Lithuanian Commonwealth.
Benjamin Franklin (1706-1790) American. Statesman, scientist, political philosopher, author. As a philosopher known for his writings on nationality, economic matters, aphorisms published in Poor Richard’s Alamanac and polemics in favor of American Independence. Involved with writing the Declaration of Independence and the Constitution of 1787.
Edward Gibbon (1737-1794) English. Historian best known for his Decline and Fall of the Roman Empire.
Johann Gottfried von Herder German. Theologian and Linguist. Proposed that language determines thought, introduced concepts of ethnic study and nationalism, influential on later Romantic thinkers. Early supporter of democracy and republican self rule.
David Hume Scottish. Historian, philosopher and economist. Best known for his empiricism and skepticism, advanced doctrines of naturalism and material causes. Influenced Kant and Adam Smith.
Immanuel Kant German. Philosopher and physicist. Established critical philosophy on a systematic basis, proposed a material theory for the origin of the solar system, wrote on ethics and morals. Influenced by Hume and Isaac Newton. Important figure in German Idealism, and important to the work of Fichte and Hegel.
Thomas Jefferson (1743-1826) American Statesman, political philosopher, educator. As a philosopher best known for the Declaration of Independence and his interpretation of the Constitution which he pursued as president. Argued for natural rights as the basis of all states, argued that violation of these rights negates the contract which bind a people to their rulers and that therefore there is an inherent “Right to Revolution.”
Hugo Ko???taj (1750-1812) Polish. He was active in the Commission for National Education and the Society for Elementary Textbooks, and reformed the Kraków Academy, of which he was rector in 1783-1786. An organizer of the townspeople’s movement, in 1789 he edited a memorial from the cities. He co-authored the Polish Constitution of May 3, 1791, and founded the Assembly of Friends of the Government Constitution to assist in the document’s implementation. In 1791-1792 he served as Crown Vice Chancellor. In 1794 he took part in the Ko?ciuszko Uprising, co-authoring its Uprising Act (March 24, 1794) and Po?aniec Manifesto (May 7, 1794), heading the Supreme National Council’s Treasury Department, and backing the Uprising’s left, Jacobin wing.
Gotthold Ephraim Lessing (1729-1781) German Dramatist, critic, political philosopher. Created theatre in the German language, began reappraisal of Shakespeare to being a central figure, and the importance of classical dramatic norms as being crucial to good dramatic writing, theorized that the center of political and cultural life is the middle class.
John Locke (1632-1704) English Philosopher. Important empricist who expanded and extended the work of Francis Bacon and Thomas Hobbes. Seminal thinker in the realm of the relationship between the state and the individual, the contractual basis of the state and the rule of law. Argued for personal liberty with respect to property
Leandro Fernández de Moratín (1760-1828) Spanish. Dramatist and translator, support of republicanism and free thinking. Transitional figure to Romanticism.
Nikolay Novikov (1744-1818) Russian. Philanthropist and journalist who sought to raise the culture of Russian readers and publicly argued with the Empress.
Thomas Paine (1737-1809) American. Pamphleteer and polemicist, most famous for Common Sense attacking England’s domination of the colonies in America.