Enlightenment philosophy


Enlightenment philosophy was the philosophy produced during the Age of Enlightenment, originating in France, then western Europe and spreading throughout the rest of Europe. The Enlightenment philosophers included Baruch Spinoza, David Hume, John Locke, Edward Gibbon, Voltaire, Jean-Jacques Rousseau, Denis Diderot, Pierre Bayle, and Isaac Newton. Enlightenment philosophy was influenced by the Scientific Revolution in southern Europe, arising directly from the Italian Renaissance with people like Galileo Galilei.
Enlightenment philosophers saw themselves as a progressive élite, and battled against religious persecution and political persecution, fighting against what they saw as the irrationality, arbitrariness, obscurantism and superstition of the previous centuries. They redefined the study of knowledge to fit the ethics and aesthetics of their time. Their works had great influence at the end of the 18th century, in the American Declaration of Independence and the French Revolution.
This intellectual and cultural renewal by the Enlightenment movement was, in its strictest sense, limited to Europe. These ideas were well understood in Europe, but beyond France the idea of "enlightenment" had generally meant a light from outside, whereas in France it meant a light coming from knowledge one gained.
In the most general terms, in science and philosophy, the Enlightenment aimed for the triumph of reason over faith and belief; in politics and economics, the triumph of the bourgeois over nobility and clergy.

Philosophical themes

Scientific Revolution

Advances in scientific method

The Enlightenment was in large part an extension of the discoveries of Nicolas Copernicus in the 16th century, which were not well known during his lifetime, and more so of the theories of Galileo Galilei. Inquiries to establish certain axioms and mathematical proofs continued as Cartesianism throughout the 17th century.
Gottfried Wilhelm von Leibniz and Isaac Newton had independently and almost simultaneously developed the calculus, and René Descartes the idea of monads. British philosophers such as Thomas Hobbes and David Hume adopted an approach, later called empiricism, which preferred the use of the senses and experience over that of pure reason.
Baruch Spinoza took Descartes' side, most of all in his Ethics. But he demurred from Descartes in Tractatus de Intellectus Emendatione, where he argued that the process of perception is not one of pure reason, but also the senses and intuition. Spinoza's thought was based on a model of the universe where God and Nature are one and the same. This became an anchor in the Age of Enlightenment, held across the ages from Newton's time to that of Thomas Jefferson's.
A notable change was the emergence of a naturalist philosophy, spreading across Europe, embodied by Newton. The scientific method – exploring experimental evidence and constructing consistent theories and axiom systems from observed phenomena – was undeniably useful. The predictive ability of its resulting theories set the tone for his masterwork Philosophiae Naturalis Principia Mathematica. As an example of scientific progress in the Age of Reason and the Enlightenment, Newton's example remains unsurpassed, in taking observed facts and constructing a theory which explains them a priori, for example taking the motions of the planets observed by Johannes Kepler to confirm his law of universal gravitation. Naturalism saw the unification of pure empiricism as practiced by the likes of Francis Bacon with the axiomatic, "pure reason" approach of Descartes.
Belief in an intelligible world ordered by a Christian God became the crux of philosophical investigations of knowledge. On one side, religious philosophy concentrated on piety, and the omniscience and ultimately mysterious nature of God; on the other were ideas such as deism, underpinned by the impression that the world was comprehensible by human reason and that it was governed by universal physical laws. God was imagined as a "Great Watchmaker"; experimental natural philosophers found the world to be more and more ordered, even as machines and measuring instruments became ever more sophisticated and precise.
The most famous French natural philosopher of the 18th century, Georges-Louis Leclerc de Buffon, was critical of this natural theology in his masterwork Histoire Naturelle. Buffon rejected the idea of ascribing to divine intervention and the "supernatural" that which science could now explain. This criticism brought him up against the Sorbonne which, dominated by the Roman Catholic Church, never stopped trying to censor him. In 1751, he was ordered to redact some propositions contrary to the teaching of the Church; having proposed 74,000 years for the age of the Earth, this was contrary to the Bible which, using the scientific method on data found in biblical concordances, dated it to around 6,000 years. The Church was also hostile to his no less illustrious contemporary Carl von Linné, and some have concluded that the Church simply refused to believe that order existed in nature.

Individual liberty and the social contract

This effort to research and elucidate universal laws, and to determine their component parts, also became an important element in the construction of a philosophy of individualism, where everyone had rights based only on fundamental human rights. There developed the philosophical notion of the thoughtful subject, an individual who could make decisions based on pure reason and no longer in the yoke of custom. In Two Treatises of Government, John Locke argued that property rights are not held in common but are totally personal, and made legitimate by the work required to obtain the property, as well as its protection by others. Once the idea of natural law is accepted, it becomes possible to form the modern view of what we would now call political economy.
In his famous essay Answering the Question: What is Enlightenment?, Immanuel Kant defined enlightenment thus:
Enlightenment philosophy was thus based on the realities of a systematic, ordered and understandable world, which required Man also to think in an ordered and systematic way. As well as physical laws, this included ideas on the laws governing human affairs and the divine right of kings, leading to the idea that the monarch acts with the consent of the people, and not the other way around. This legal concept informed Jean-Jacques Rousseau's theory of the social contract as a reciprocal relationship between men, and more so between families and other groups, which would become increasingly stronger, accompanied by a concept of individual inalienable rights. The powers of God were moot amongst atheist Enlightenment philosophers.
The Enlightenment redefined the ideas of liberty, property and rationalism, which took on meanings that we still understand today, and introduced into political philosophy the idea of the free individual, liberty for all guaranteed by the State backed by a strong rule of law.
To understand the interaction between the Age of Enlightenment and the Enlighteners, one approach is to compare Thomas Hobbes with John Locke. Hobbes, who lived for three quarters of the 17th century, had worked to create an ontology of human emotions, ultimately trying to make order out of an inherently chaotic universe. In the alternate, Locke saw in Nature a source of unity and universal rights, with the State's assurance of protection. This "culture revolution" over the 17th and 18th centuries was a battle between these two viewpoints of the relationship between Man and Nature.
This resulted, in France, in the spread of the notion of human rights, finding expression in the 1789 Declaration of the Rights of Man and of the Citizen, which greatly influenced similar declarations of rights in the following centuries, and left in its wake global political upheaval. Especially in France and the United States, freedom of expression, freedom of religion and freedom of thought were held to be fundamental rights.

Social values and manifests

Representation of the people

The core values supported by the Enlighteners were religious tolerance, liberty and social equality.
In England, America and France, the application of these values resulted in a new definition of natural law and a separation of political power. To these values may be added a love of nature and the cult of reason.

Philosophical goals

The ideal figure of the Enlightenment was a philosopher, a man of letters with a social function of exercising his reason in all domains to guide his and others' conscience, to advocate a value system and use it in discussing the problems of the time. He is a committed individual, involved in society, an honnête homme qui agit en tout par raison, qui s'occupe à démasquer des erreurs.
The rationalism of the Enlightenment was not to the exclusion of aesthetics. Reason and sentiment went hand-in-hand in their philosophy. The thoughts of Enlightenment philosophers were equally capable of intellectual rigour and sentimentality.
Despite controversy about the limits of their philosophy, especially when they denounced black slavery, many Enlightenment philosophers criticised slavery, or colonialism, or both, including Montesquieu in De l'Esprit des Lois, Denis Diderot in Supplément au voyage de Bougainville, Voltaire in Candide and Guillaume-Thomas Raynal in his encyclopaedic Histoire des deux Indes, the very model of 18th-century anticolonialism to which, among others, Diderot and d'Holbach contributed. It was stated without any proof that one of their number, Voltaire, had shares in the slave trade.

Encyclopaedic goals

At the time, there was a particular taste for compendia of "all knowledge". This ideal found an instance in Diderot and d'Alembert's Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers, usually known simply as the Encyclopédie. Published between 1750 and 1770 it aimed to lead people out of ignorance through the widest dissemination of knowledge.