In Lecture 20 we saw how the intellectual climate during the Enlightenment was dominated by science and that questions of science were discussed regularly in every respectable household. It is only logical that such pervasiveness of science in the public mind should have repercussions in other fields of human intellectual endeavour.
In this lecture we look at the impact of science on philosophy. We will not add anything new to the development of scientific ideas; traditional History of Science texts do not include any of the material discussed in this lecture. Instead, we shall concentrate on the development of philosophy under the intellectual climate of the Enlightenment and discover a most significant development: the establishment of science and philosophy as separate human activities and the separation of philosophy from religion.
Let us recall that initially science and religion were closely linked and did not appear as separate endeavours of the human mind until shortly after 1000 BC during the new age of science in Greece, when the new discipline of philosophy emerged (see Lecture 8). Philosophy in Greece still relied much on unverifiable beliefs, but unlike religion it attempted to understand nature without recourse to divine forces.
As long as scientists tried to explain the world mainly through intellectual argument, science remained part of the philosophy of nature. This was the situation in all civilizations for the next 2,500 years until the European Renaissance began to place scientific study firmly on the basis of observation and experiment.
The resulting scientific revolution led to the separation of science from philosophy, which by its very nature had to continue in the tradition of intellectual argument as its means of study. But the scientific revolution shaped the methodology of philosophy, and in the end science, philosophy and religion emerged as three distinct disciplines of intellectual endeavour.
Every civilization has the need to take stock of its understanding of the world from time to time and summarize its knowledge. Revolutions in science and society are times when this need is felt particularly strongly.
A collection of the knowledge of a society is called an encyclopaedia (Greek enkyklios paideia "general education"). The scientific revolution in Greece produced the first European encyclopaedia. It was written by Speusippus, a nephew of Plato's, and covered his uncle's ideas on natural history, mathematics, philosophy and other aspects of life. Plato and his student Aristotle did not write encyclopaedic works themselves, but both lectured widely on every aspect of human thought (see Lecture 8) and can in that sense be regarded the originators of the encyclopaedia in Europe.
The Roman civilization produced the Historia naturalis of Pliny the Elder in 77 AD, the first encyclopaedia based on some kind of classification of its content. Although its author was uncritical towards his sources and included much fanciful material, his work served as a major source for other encyclopaedias of the European tradition for at least the next 1,500 years. The encyclopaedia of Celsus, which was written at about the same time but survived only in its parts related to medicine, was equally influential for 1,500 years.
The Chinese civilization produced encyclopaedias for approximately 2,000 years. These works were mainly anthologies of significant literature compiled by scholars of eminence. They were written as books of instruction for candidates of the civil service, and in keeping with the static character of the Chinese civilization they were revised over the centuries rather than rewritten. The first known Chinese encyclopaedia, the Huang-lan ("Emperor's Mirror"), was written in about 220 AD. A compendium of medical knowledge, the Yellow Emperor's Canon of Medicine, had already appeared in about 100 BC, and a second compendium of medical science was written at the time of the Emperor's Mirror (see Lecture 15).
The first true encyclopaedia of the Arab civilization was the work of the teacher Ibn Qutayba (828-889). The 10 books of his Kitab 'Uyun al-Akhbar ("The Best Traditions") was based on traditional aphorisms, historical examples, and old Arabic poems and arranged into the categories power, war, nobility, character, learning and eloquence, asceticism, friendship, prayers, food, women. It provided the framework for many works that followed. The first thoroughly scientific Islamic encyclopaedia was written by al-Khwarizmi. His Mafatih al-'Ulum ("Key to the Sciences") was compiled in 975-997. Its division into indigenous knowledge (jurisprudence, scholastic philosophy, grammar, secretarial duties, prosody and poetic art, history) and foreign knowledge (philosophy, logic, medicine, arithmetic, geometry, astronomy, music, mechanics, alchemy) reflected the assimilating character of the Islamic civilization (see Lecture 16).
The great upheaval of European thought during the 15th and 16th centuries created the first attempt at an all-embracing European encyclopaedia. At the time when Kepler formulated his laws and Galilei collected observational proof that the Earth revolves around the Sun, Francis Bacon worked on his Instauratio Magna, an undertaking of mammoth proportions.
Bacon lived under Elizabeth I and her successor James I. It was a time when success in public life depended on participation in court intrigue and when a career in politics almost inevitably involved moral and ethical compromise. Bacon was strongly attracted to politics and as a man of his time did not shy away from sycophantism and trickery to achieve his aims. He had a few successes but was also briefly imprisoned and after his release only ever managed to be allowed to kiss the king's hand.
But Bacon was a man of outstanding intellect, excellent writing skills and unlimited ambition, which drove him to devise the Instauratio Magna, a plan for a classification and description of all knowledge, or in his own words an attempt "to commence a total reconstruction of sciences, arts, and all human knowledge, raised upon the proper foundations". Like many others of his grand designs, his Instauratio Magna was never completed; but those parts that were published had the greatest impact on the development of human thought in Europe. His classification system divided knowledge into four main areas:
Bacon's classification appears fanciful today but can be understood from the perspective of his time. His placing of physics under speculative philosophy reflects the controversy between the Ptolemaic and Copernican system, which was still unresolved during Bacon's lifetime (see Lecture 20). The innovative aspect of Bacon's classification is his separation of philosophy from religion (theology). Before Bacon all philosophical thought began with and developed from the relationship between God and Man. Bacon relegated this relationship to theology and established philosophy as the area where the human mind explores the laws of nature.
One century after Bacon the Age of Reason in Europe brought about a real flood of encyclopaedias. They ranged from what today would be called "popular science" to collections of original articles for the educated elite. It began with the Cyclopaedia, a two volume work described by his editor Ephraim Chambers as "an universal dictionary of arts and sciences; containing an explication of the terms, and an account of the things signified thereby, in the several arts, both liberal and mechanical, and the several sciences, human and divine, compiled from the best authors."
Title |
Country of Publication |
First Edition |
Cyclopaedia |
England |
1728 |
Encyclopédie |
France |
1751 - 1765 |
Encyclopædia Britannica* |
England (since 1920 USA) |
1768 - 1771 |
Konversationslexikon |
Germany |
1796 - 1811 |
Encyclopedia Americana* |
USA |
1829 - 1833 |
The various encyclopaedias reflected the social development of their countries. Britain was the most advanced of all European nations when it came to commerce and industry, and the Cyclopaedia by Ephraim Chambers and the first edition of the Encyclopædia Britannica were both driven more by a desire for profit than scientific interest; they were simply collections of articles reprinted from magazines and other sources. The German Konversationslexikon ("Dictionary for Conversation") indicated its purpose in its title: It was designed to spare the respectable bourgeois any embarrassment in after dinner conversation. The purpose of the Encyclopedia Americana was the assertion of the United States of America as an independent country; it concentrated on articles about north American achievements.
The French Encyclopédie was of a very different kind. French intellectuals admired the freedom of thought and open debate that reigned in England, and when the idea of a French encyclopaedia was first proposed its editor Denis Diderot tried to arrange a translation of Chambers' work. When this fell through in 1745 Diderot set about to write material himself. The result was the Encyclopédie, Ou Dictionnaire Raisonné Des Sciences, Des Arts Et Des Métiers ("Encyclopaedia, or Classified Dictionary of Sciences, Arts, and Trades").
The Encyclopédie had a profound impact on the social development of France. In its liberal attitude, its emphasis on scientific determinism and its criticism of the abuses perpetrated by contemporary legal, judicial, and clerical institutions it was not just a collection of knowledge but a philosophical statement and a herald of the French Revolution. As could be expected it was attacked by conservative forces from its very beginning and went through various bans and attempts of censorship. But this only improved the quality of its content, since Voltaire, Rousseau and other famous intellectuals were attracted to it and became authors of contributions.
The first 17 volumes of the Encyclopédie were published before 1765. Many more volumes followed. All organized their entries in alphabetical order and identified their authors by name. A systematic classification was adopted in 1782 and the title of the work changed to Encyclopédie méthodique ou par ordre de matières ("Systematic Encyclopaedia or Arranged by Subject"). The final 166th volume of this work appeared in 1832.
Much of Diderot's criticism was of course directed against the feudal regime, but he did not shirk from confrontation with the new ruling class when he found it in conflict with its own ideals. For the bourgeoisie "Liberty, Equality and Brotherhood" was a useful rallying cry for the revolutionary masses but had no meaning in the distant world, where unexplored territories were waiting to be taken over as colonies. When the explorer Compte de Bougainville wrote glowing reports of possible new possessions in the South Pacific, Diderot responded with his Supplement to a Voyage of Bougainville. His defence of the islanders was coloured by romantic images of the South Pacific as Paradise on Earth; but in his arguments he confronted the plans of the bourgeoisie to dispossess and enslave the islanders with its own ideal of Equality:
It was a first sign that philosophy was not going to stop where capitalism had established itself but would soon turn its criticism towards the new capitalist order itself.
As a contemporary of Kepler and Galilei, Bacon had witnessed the rise of the new science and the ensuing debate but could not foresee its final outcome. A century later the English philosopher John Locke was a member of the recently established Royal Society and had ample opportunity for contact with Newton and other scientists. The formulation of Newton's Laws in 1679 had a great impact on all areas of thought, and Locke saw scientists as the true philosophers because they advanced knowledge from experience and analysis.
The starting point of Locke's philosophy was the notion that reasoning cannot reveal anything about nature unless it is based on perception of the senses. Just like the scientist, who starts his reflection on the laws of nature from experiment and observation, the philosopher has to start reasoning from observed facts. Reflection of perceived physical objects then produces the ideas that represent the objects in one's mind.
In 1689 Locke published An Essay Concerning Human(e) Understanding, the culmination of decades of thought. The modest title of the work does not do justice to its wide-ranging content. In several volumes it covered areas as far apart as general philosophy, psychology, linguistics, sociology and political economy. Locke was among the first to analyse the basic laws of capitalism; his analysis of the value of labour as a contribution to the general wealth of society expressed the core ideas of the theory of value, developed further a century later by Adam Smith and another century later by Karl Marx.
Locke's Essay appeared in print one year after the "Glorious Revolution," which had guaranteed freedom of thought. The publication of his work was therefore never in doubt. Half a century later the Baron de Montesquieu continued the analysis of the laws under which people live in various societies. France was still more than 40 years away from its revolution when he published De l'esprit des loix ("The Spirit of Laws") in 1748. On over 1,000 pages in 31 books he developed the political theory of society. It was immediately admired as one of the greatest achievements of the Enlightenment but also attacked by the Catholic church.
Two years after the publication of his work Montesquieu tried to deflect the criticism by publishing the Défense de L'Esprit des loix. It did not help; a year later the Catholic church placed De l'esprit des loix on its list of banned books.
Although Montesquieu formulated most of his ideas at the idyllic retreat of his Chateau de Brède there can be no doubt that his attitude to the problem of democratic government and other aspects of society was deeply formed by his experience with the advances of science in the capital cities of Europe. During his brief stay in England he was elected a Fellow of the Royal Society, and although he mostly sought contact with personalities of public political life he also met and conversed with leading scientists.
In De l'esprit des loix Montesquieu developed a scientific approach to the theory and historical development of governments. The division of power into an independent Legislative, Executive and Judiciary, the cornerstone of modern parliamentary democracy, is one of the central elements of his theory.
T he Scottish philosopher David Hume belonged to the generation after Montesquieu but began to write when he was 23 years old. Parts I and II of his first major work were therefore published nine years before De l'esprit des loix. Its title spelled out Hume's plan for his undertaking: A Treatise of Human Nature: Being an Attempt to Introduce the Experimental Method of Reasoning into Moral Subjects. In plain words, what Hume was trying to achieve was to introduce scientific methods into philosophy.
The immediate result was of course an accusation of atheism and the placing of his books on the list of banned literature by the Catholic church. But Hume found time to study and refine his work, and during a stay in Paris he met Rousseau and other philosophers and found much support.
Hume's philosophical system was an attempt to merge the scientific method, which derives laws of nature from observation and experiment, with Locke's system of "reflection" of perceived physical objects and "ideas" as their representation in one's mind. Hume distinguished between the collection of data or "impressions," and the "ideas" that are derived from the data: There are no ideas without observations.
The analysis of the process of understanding as a move from impressions to ideas is of course only a small part of philosophy. Hume covered it in book I of his Treatise. Book II was "on Passion," book III "on Morals." Hume never doubted that it is possible to establish a standard of good and evil without recourse to religion - he followed Montesquieu on this point - but found it difficult to apply the scientific principle of causality to questions of passion and moral. Undisputable connection between cause and effect was of course the basis for the physical laws that Newton had discovered; but how could such a rigid connection be established between observed human action and the "laws" of ethics? Hume could not answer this question.
Hume's contemporary Jean-Jacques Rousseau solved the problem by postulating the natural goodness of humanity. Rousseau was born and grew up in Geneva, a bulwark of Calvinism. As a Calvinist he was of course aware of the Christian teaching of the original sin. But his mentor and lover Baroness de Warens managed to change Rousseau's outlook on life at least to a degree, and Rousseau owes much of his success as a philosopher to her.
The assumption that humans are good by their very nature opened a long list of questions. Why are some people free, while others are enslaved? Why is there such inequality in wealth? How did the present inequality arise from the assumed society of good and free men and women? In 1755 Rousseau published his Discours sur l'origine de l'inegalité ("Discourse on the Origin of Inequality"), in which he presented a reconstruction of human history from a presumed state of innocence to the 18th century.
According to the Discours the key to the many injustices of contemporary society was private property, which Rousseau called a "fatal concept". This was of course a direct attack on the most important pillar of capitalism and could only result in persecution. But Rousseau's next work Du contrat social, ou principes du droit politique ("The Social Contract, or Principles of Political Law"), published in 1762, continued the argument with the opening sentence "Man was born free, but he is everywhere in chains."
It may be surprising that Rousseau's difficulties with the Catholic church did not stem so much from his philosophy as from his prose. Rousseau was not the introspective intellectual people usually associate with philosophers, and his literary works, in which he described how to educate young men and women to find their place in his ideal society, made pleasant reading and found a wide readership. Rousseau's novels signified the transition from the Age of Reason to the Romanticism that dominated the beginning of the 19th century. Their promotion of love as the basis of marriage and their free expression of emotions brought him the wrath of the Catholic church, and Rousseau spent many years on the run from the authorities.
Compared to the free tone of his novels Rousseau's philosophical conclusions were rather restraint. Having raised the question of original freedom, the Contrat social solves the apparent injustice of history by stating that men find political liberty in obeying self-imposed law. Rousseau was no revolutionary; he accepted the need for authority to stop people from straying off the good path.
At the same time when Rousseau moved towards Romanticism Immanuel Kant, professor at the University of Königsberg in Prussia (today's Kaliningrad in Russia) attempted to find an answer to Hume's problems as well. Kant was educated in physics and mathematics; he had read Newton's works and at the age of 20 decided to write his own book on physics. After completion of his studies he was appointed lecturer in mathematics and physics in 1755, but his interest turned to systematic philosophy, and his book on physics did not materialize.
It took Kant another 15 years before he was appointed professor of logic and metaphysics in 1770 and could concentrate on his interest full-time. His plan was clear: He wanted to apply the scientific method to all areas of philosophy. The result were three books, published just before and during the French Revolution:
In Kant's sense "critique" was not meant to be critical in a negative sense; on the contrary, he dedicated his "Critique of Pure Reason" to Francis Bacon, and all three books developed as a collegial disputation with Hume's Treatise. Kant's Critique was meant to be a critical evaluation of all philosophy and its reconstruction, based on scientific principles, from the ground up.
Kant's books were written in a tedious style, and few people find them pleasant reading. Among most people their author is probably better known for his Prussian self-discipline and utterly organized lifestyle than by his philosophy. But of all the philosophers who tried to respond to the scientific revolution by making philosophical concepts more rigorous, Kant was the most successful and influential. His work allowed Friedrich Hegel to complete the process of separation between philosophy and religion.
Hegel saw the development of the human mind as a rise through stages. In his work Die Phänomenologie des Geistes ("The Phenomenology of Mind"), published in 1807, he described these stages as a succession from consciousness to self-consciousness, followed by reason, spirit, religion and finally absolute knowledge.
It is tempting to interpret this sequence as an evolution in which each stage is superior to the previous stage and thus replaces it. But the idea that religion is superseded by scientific knowledge was far from Hegel's mind. On the contrary, Hegel always saw philosophy as part of God's plan and an instrument for its implementation.
Regardless of his own religious beliefs it is clear that Hegel was absolutely convinced of the scientific approach as the only correct approach to philosophy, to the extent that he attempted to overcome the separation of science and philosophy by making philosophy another discipline of science: He published "The Phenomenology of Mind" as Part One of a planned larger work System der Wissenschaft ("The System of Science"), and his second major work carried the title Die Wissenschaft der Logik ("The Science of Logic"). In 1817 - 1818, fifteen years after the French Revolution and two years after Napoleon's final defeat at Waterloo, he published the Encyklopaedie der philosophischen Wissenschaften ("Encyclopaedia of the Philosophical Sciences").
The introduction of the scientific method into philosophical studies had not only led to a new assessment of classical philosophical problems, it also opened the avenue for a scientific approach to the laws underlying society. In the 17th century Locke had already made an attempt to analyse the relationship between labour and property. Adam Smith, a contemporary of Kant and a Fellow of the Royal Society, began the systematic analysis of the laws of capitalism, laying in the process the basis for the science now called political economy.
Smith witnessed the chaos and suffering during early capitalism, when thousands and thousands of peasants were forced off their land to become available as the labour force for the sprouting factories, and asked how the individual capitalists, who were only interested in their own profit, "led by an invisible hand . . . without knowing it, without intending it, advance the interest of the society." The result was his famous work An Inquiry into the Nature and Causes of the Wealth of Nations, published in 1776.
Smith's analysis was based on assumed laws of human nature, which he saw as driven by the contradicting forces of passion, reason and capacity for sympathy. This approach could not be justified today. (Lecture 27 will discuss how our understanding of the laws of human nature has evolved since the 18th century.) But Smith experienced capitalism in its early stages and had a very limited set of observations at his disposal. Given these limitations, his work contains some extraordinarily advanced insights into the history of human society.
In the Wealth of Nations Smith developed a model of human society from the original state of hunter-gatherers through nomadic agriculture and the agriculture of large estates under feudalism to capitalism and discussed the political institutions of each stage. He identified the occurrence of private property as the reason for social inequality and stated that
Despite this clear appreciation of the class character of government Smith came to the conclusion that capitalism is the system of perfect liberty, because it is driven by the many free decisions of individuals, who unknowingly and not necessarily with intent drive society forward.
Smith's study of the laws of the capitalist economy anticipated much of the analysis undertaken by Karl Marx nearly a century later (see Lecture 27). Smith described the mechanism of economic growth based on division of labour and increased scale of the industrial process and anticipated the decline of the rate of profit and eventual stagnation. Unlike Marx, Smith had no experience of trade unions or socialist parties. His model of capitalist society therefore did not include organized class action; it relied on the actions of individuals as the motor of society.
We have seen how the scientific revolution led to the introduction of the scientific method (observation and experiment as the basis of the derivation of general laws) into all areas of intellectual activity and to the separation of philosophy from religion. The immediate question that arises is: Did the Age of Reason, with its scientific revolution, spell the end of religion as a justifiable part of human intellectual endeavour?
Hegel's attitude to the question is instructive in this respect. In 1798 he wrote: "Church and state, worship and life, piety and virtue, spiritual and worldly action can never dissolve into one." In his view his "Philosophical Sciences" did not replace religion; they co-exist with religion and do not overlap. But if physics can explain the laws of the inanimate world, evolution (to be discussed in Lecture 25) the development of the animate world, philosophy the rules of language and thought, and political economy the laws of societies, how much is left for religion if it is not to overlap with philosophy and science?
Whatever progress science and philosophy will make, there is one question both cannot answer. Science and philosophy will continue to make progress on the question how the world works; they can never explain why the world exists. Many may say that this is an idle question, because it is irrelevant to our daily lives. But many others find it essential to believe in an answer, and they find it in religion. Different religions offer different answers, but all aim at answering the questions: Why are we here? What is the meaning of life?
It is thus possible to separate philosophy (which for Hegel includes science) from religion by allocating to philosophy the inquiry into the "How" and to religion the inquiry into the "Why" and leave the decision whether the second question is superfluous or not to the individual. However, before the Age of Reason religion not only explained why the world exists but served also to define the ethics of a society. If religion is now removed as a necessity of the human condition and left as an optional extra, what sets the standards of ethical behaviour and decides what is not socially acceptable?
The philosophers of the Enlightenment were acutely aware of this problem and offered various solutions. Shaftsbury suggested: "Help those in distress, if you sympathize with their sufferings!" as a basic principle of ethics. Kant called such suggestions hypothetical imperatives, because their value as an ethical principle depends on the wishes of the individual. He gave the example "Be honest, so that people will think well of you!" and queried whether every member of a society does actually care what people think of them. Compared to such hopeful statements religion has the advantage that the ethics it preaches is set by divine decision, applies to everyone and does not leave room for ambiguity.
Observation shows that, as Hegel put it, piety and virtue can never dissolve into one. A pious person can be virtuous, and many are; but there are also plenty of examples of outwardly pious people who live amoral lives and perpetrate unethical acts, while Diderot and Montesquieu are just two examples of atheists with high moral standards and respect for ethical values.
Observation thus suggests that some ethical principles are universal and do not require religious support to be accepted by people. The fact that all religions have as their core the same set of ethical principles and the same standards by which human actions can be judged as right or wrong also suggests that the human race is endowed with an ingrained ethical code that is independent of any particular religion.
The separation of philosophy from religion made the discovery of this ethical code one of its most important tasks. Rousseau's answer - that all humans are originally good - is contradicted by observation, as is the Christian doctrine of the original sin. Anyone who watches small "innocent" children play in a group can see that children can be vicious and cruel but also compassionate and altruistic. The question of ingrained ethics is more complicated than a simple choice between naturally good or naturally evil.
Kant solved the problem by introducing his "categorical imperative," which turns an ethical principle into the basic law of human co-existence: "Act only on that maxim through which you can at the same time will that it should become a universal law." (Encyclopaedia Britannica, 1995)
This very brief overview of the development of philosophy during the Age of Reason has to suffice at this point. Questions of ethics will occupy us again as we get closer to the 20th century, and some answers to the question of ingrained ethical principles will be discussed when we look at evolution and heredity in Lecture 34. The main point of the discussion of this lecture was the impact of the scientific revolution on philosophy, which was moved into its own revolution by drawing a line between itself and religion.
Ethics. Encyclopaedia Britannica 15th ed. (1995)
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