Age Of Enlightenment

The Age of Enlightenment, sometimes called the Age of Reason, refers to the time of the guiding intellectual movement, called The Enlightenment. It covers about a century and a half in Europe, beginning with the publication of Francis Bacon's Novum Organum (1620) and ending with Immanuel Kant's Critique of Pure Reason (1781). From the perspective of socio-political phenomena, the period is considered to have begun with the close of the Thirty Years' War (1648) and ended with the French Revolution (1789).

The Enlightenment advocated reason as a means to establishing an authoritative system of aesthetics, ethics, government, and even religion, which would allow human beings to obtain objective truth about the whole of reality. Emboldened by the revolution in physics commenced by Newtonian kinematics, Enlightenment thinkers argued that reason could free humankind from superstition and religious authoritarianism that had brought suffering and death to millions in religious wars. Also, the wide availability of knowledge was made possible through the production of encyclopedias, serving the Enlightenment cause of educating the human race.

The age of Enlightenment is considered to have ended with the French Revolution, which had a violent aspect that discredited it in the eyes of many. Also, Immanuel Kant (1724-1804), who referred to Sapere aude! (Dare to know!) as the motto of the Enlightenment, ended up criticizing the Enlightenment confidence on the power of reason. Romanticism, with its emphasis upon imagination, spontaneity, and passion, emerged also as a reaction against the dry intellectualism of rationalists. Criticism of the Enlightenment has expressed itself in a variety of forms, such as religious conservatism, postmodernism, and feminism.

The legacy of the Enlightenment has been of enormous consequence for the modern world. The general decline of the church, the growth of secular humanism and political and economic liberalism, the belief in progress, and the development of science are among its fruits. Its political thought developed by Thomas Hobbes (1588-1679), John Locke (1632-1704), Voltaire (1694-1778) and Rousseau (1712-1788) created the modern world. It helped create the intellectual framework not only for the American Revolutionary War and liberalism, democracy and capitalism but also the French Revolution, racism, nationalism, secularism, fascism, and communism.

Enlightenment thought

The intellectual leaders of the Enlightenment regarded themselves as a courageous elite who would lead the world into progress from a long period of doubtful tradition and ecclesiastical tyranny, which had resulted in the bloody Thirty Years' War (1618-1648) and the English Civil War (1642-1651). This dogmatism took three forms:

1. Protestant scholasticism by Lutheran and Calvinist divines,^[1]
2. "Jesuit scholasticism" (sometimes called the "second scholasticism") by the Counter-Reformation, and
3. the theory of the divine right of kings in the Church of England.

(A later, religious reaction against the church's dogmatic outlook was the Pietist movement of the seventeenth and eighteenth centuries.)

Enlightenment thinkers reduced religion to those essentials which could only be "rationally" defended, i.e., certain basic moral principles and a few universally held beliefs about God. Aside from these universal principles and beliefs, religions in their particularity were largely banished from the public square. Taken to its logical extreme, the Enlightenment resulted in atheism.

Philosophy

In the seventeenth century, Francis Bacon (1561-1626) pointed out intellectual fallacies of the older tradition, and René Descartes (1596-1650) made doubting the first principle of philosophy; and these set much of the agenda as well as much of the methodology for those who came after them. The age of Enlightenment is typified in Europe by the great system-builders—philosophers who present unified systems of epistemology, metaphysics, logic, and ethics. Immanuel Kant later classified his predecessors into two schools: The rationalists and the empiricists. This division may be an oversimplification, but it has continued to be used to this day, especially when writing about the seventeenth and eighteenth centuries. The three main rationalists are normally taken to have been René Descartes, Baruch Spinoza (1632-1677), and Gottfried Leibniz (1646-1716). Building upon their English predecessors Francis Bacon and Thomas Hobbes (1588-1679), the three main empiricists were John Locke (1632-1704), George Berkeley (1685-1753), and David Hume (1711-1776). The former were distinguished by the belief that, in principle (though not in practice), all knowledge can be gained by the power of reason alone; the latter rejected this, believing that all knowledge has to come through the senses, from experience. Thus the rationalists took mathematics as their model for knowledge, and the empiricists took the physical sciences.

Enlightenment religion

The spirit of the Age of Reason also affected Christianity. Depending on how much it affected Christianity, there occurred two distinguishable schools in the religion of the Enlightenment: Rational supernaturalism and Deism.

Rational supernaturalists included William Chillingworth (1602-1644), John Tillotson (1630-1694), and John Locke. While they understood the unique role of revelation and differentiated between what could and what could not be rationally established, they were convinced that revelation could still be defended by reason. For them, while revelation may be above reason, it is not contradictory to reason. In his The Reasonableness of Christianity as Delivered in the Scriptures (1695), Locke argued that while the miracles recorded in the Bible can indicate their divine origin, reason has the last word in explaining and accepting them. Rational supernaturalists also believed that Christian revelation can be reduced to a few doctrinal essentials about God, which can provide the divine sanctions for morality.

More radical than rational supernaturalism was Deism, which denied the necessity of revelation, by maintaining that after creating the universe, God does not interfere in its day-to-day runnings. Deists included John Toland (1670-1722) and Matthew Tindall (1655-1733) in England, Voltaire (1694-1778) in France, and Hermann Samuel Reimarus (1694-1768) and Gotthold Ephraim Lessing (1729-1781) in Germany. In his Christianity Not Mysterious (1696), Toland asserted that God's revelation is not above reason, and attributed the mysteries of the Christian faith, allegedly originated from revelation, to priestcraft and paganism. Tindall's Christianity as Old as the Creation (1730), which was regarded as the "Bible" of deism in the eighteenth century, argued that the universal "religion of nature" was already perfect and unalterable from the beginning when the world was created, like God is always perfect and unchangeable, and that historical revelation adds nothing to this religion. Tindall this way critiqued what he thought to be the unnecessary "superstitions" of the Bible and the church. Voltaire's early deism was more quietly philosophical, but later in his life a few critical events, such as the execution of a Huguenot in 1762, led him to more polemically attack the institutionalized fanaticism of Christianity. In place of Christianity, he envisioned a new, practical deistic religion, according to which one has only to believe in one just God without any ritual and to practice virtue. Reimarus subjected the whole biblical history and Christianity to critical analysis based upon reason. In Germany, Johann Gottfried von Herder (1744-1803) 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 such as the Bible was open to deeper exploration based on deeper connections, an idea now called hermeneutics.

So-called philosophes (French for philosophers), many of whom contributed articles to the Encyclopédie, were mainly Deists.

Science

The heliocentric theory of Nicolaus Copernicus (1473-1543) started what historians call the "scientific revolution." This scientific revolution, based on experimentation and reason, questioned previously held truths and searched for new answers. It modified the medieval view of the world and human beings' relation to it. It thus helped shape the Enlightenment.

Galileo Galilei (1564-1642) made the first systematic studies of uniformly accelerated motion and improved astronomical observations, which helped to support Copernicanism. Edmond Halley (1656-1742) discovered the proper motion of stars and the periodicity of comets. Other significant scientific advances were made by Johannes Kepler (1571-1630), Blaise Pascal (1623-1662), Christiaan Huygens (1629-1695), Robert Hooke (1635-1703), and Gottfried Leibniz.

Isaac Newton (1643-1727) combined mathematics of axiomatic proof with mechanics of physical observation and established a coherent system of verifiable predictions in his Philosophiae Naturalis Principia Mathematica (1687). His greatest claim to prominence came from a systematic application of algebra to geometry, which synthesized a workable calculus applicable to scientific problems. 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.

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 (1738-1822), and the calculation of the mass of the Sun using Newton's theory of universal gravitation. These series of discoveries had a momentous effect on both pragmatic commerce and philosophy. The excitement engendered by 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, greatly influenced both religious and secular ideas. If Newton could order the cosmos with natural philosophy, so, many argued, could political philosophy order the body politic.

Political thought

Europe had been ravaged by religious wars; when peace in the political situation had been restored, after the Peace of Westphalia (1648) and the English Civil War (1642-1651), an intellectual upheaval overturned the accepted belief that mysticism and revelation are the primary sources of knowledge and wisdom—which was blamed for fomenting political instability. Instead, the Age of Reason sought to establish axiomatic philosophy as a foundation for stability.

The seventeenth century saw the birth of some of the classics of political thought, especially Thomas Hobbes' Leviathan (1651), and John Locke's Two Treatises of Government (1690). They were basically against the notion of the divine right of the kings, according to which the king derives his right to rule from the will of God and not from any temporal authority, including the will of his subjects, the aristocracy, or any other estate of the realm, so that any attempt to depose the king or to restrict his powers runs contrary to the will of God. Hobbes argued that it is by natural law and contract that sovereignty is to be transferred to the king or monarch, because it is ultimately derived from the people and not from the divine right. Locke proposed an even more democratic view, maintaining that the purpose of authority is to protect human equality and freedom. According to him, citizens agree to a "social contract" that places an authority over them, but if that authority ceases to care for their welfare, independence, and equality, then the contract is broken and it is the duty of the members of society to overthrow the ruler. His Two Treatises was published shortly after the Glorious Revolution of 1688, clearly reflecting the political fallout from that event. It had a decisive influence in the occurrence of the American War of Independence and the French Revolution and in the development of liberalism, democracy, and constitutional governments which followed.

Other political thinkers include Montesquieu (1689-1755) and Jean-Jacques Rousseau (1712-1778). Montesquieu defined three forms of government: Republics, monarchies, and despotisms, and undoubtedly preferred republics where, according to him, the three governmental powers of legislative, executive, and judicial are to be separated. Rousseau's Du contrat social (1762) presented his theory of the just state centering on the general will of the people expressed in the laws.

During the age of Enlightenment, there was so-called "enlightened despotism," a form of despotism where the rulers were influenced by the Enlightenment. Strictly speaking, these "enlightened" rulers were distinguished from the kings of the divine right in that the former embraced the basic principles of the Enlightenment such as reason and humanism. For example, Joseph II of the Holy Roman Empire (ruling 1765-1790) is said to have fully embraced the concept of social contract. Frederick the Great of Prussia (ruling 1740-1786), too, maintained the ideals of the Enlightenment, although he still permitted the practice of serfdom. In nineteenth century Russia, Alexander II adopted Enlightenment ideas and liberated the serfs. Eventually, even enlightened despotism was destined to be replaced in the course of history.

The Scottish Enlightenment

Scotland benefited economically from the expansion of trade and commerce of the British Empire in the seventeenth through to the twentieth centuries. Many Scots served overseas in the colonial service and also engaged in commerce. Traditionally close ties to France from the pre-Union with England period helped to forge intellectual links with French thought. Scotland's universities were less subject to ecclesiastical control than Oxford and Cambridge were, and a type of humanism flourished in the Scottish academy. Several writers, such as Arthur Herman and James Buchan, point to the high level of Scottish contributions to Enlightenment thought, represented by such thinkers as Francis Hutcheson (1694-1746), David Hume, and Adam Smith (1723-1790).^[2] The concept of "free trade," the mainstay of globalization as well as much of what came to be known as "scientific method" developed within the Scottish Enlightenment. Herman explores how Scotland's 1707 union with England transformed the country from one of the poorest in Europe to an affluent and highly educated society, giving birth to the Scottish Enlightenment.

Role of the Enlightenment in later philosophy

The Enlightenment occupies a central role in the justification for the movement known as modernism. The neo-classicizing trend in modernism came to see itself as being a period of rationality which was overturning foolishly established traditions, and therefore analogized itself to the Encyclopedists and other philosophes. A variety of twentieth century movements, including liberalism and neo-classicism traced their intellectual heritage back to the Enlightenment, and away from the purported emotionalism of the nineteenth century. Geometric order, rigor, and reductionism were seen as virtues of the Enlightenment. The modern movement points to reductionism and rationality as crucial aspects of Enlightenment thinking, of which it is the inheritor, as opposed to irrationality and emotionalism. One notable school in this connection is positivism, which Auguste Comte (1798-1857) started in the empiricist tradition, a segment of the Enlightenment.

In this view, the Enlightenment represents the basis for modern ideas of liberalism against superstition and intolerance. Influential philosophers who have held this view are Jürgen Habermas (1929- ) and Isaiah Berlin (1909-1997). 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 in 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.

Critiques of the Enlightenment

Critiques from Hume and Kant

In spite of its great contributions to the awareness of human dignity and the development of science, the Enlightenment apparently had its own limitations. So, from within the tradition of the Enlightenment, there emerged some notable critiques of the Enlightenment, such as Hume's skepticism and Kant's critical philosophy. Hume's thoroughgoing empiricism resulted in his skepticism about causality, thus destroying the rationalistic approach to God and the world. Kant decided that while pure reason may know the phenomenal world of causation, it cannot know God, freedom, and afterlife, which can only be postulated through faith in the moral sense of duty. This way, the claim of reason to sole validity in the Enlightenment started to decline.

Political conservatism

The French Revolution was a political outcome of the Enlightenment. So, its violent extremes (particularly during the Reign of Terror) fueled a major reaction against the Enlightenment, which many writers blamed for undermining traditional beliefs that sustained the ancien regime, thereby fomenting revolution. Counter-revolutionary conservatives such as Irish politician Edmund Burke (1729-1797), French Jesuit Augustin Barruel (1741-1820), and French writer Joseph de Maistre (1753-1821) all asserted a close link between the Enlightenment and the French Revolution, as did many of the revolutionary leaders themselves, so that the Enlightenment became increasingly discredited as the French Revolution became increasingly bloody. Burke's Reflections on the Revolution in France (1790) was heavily spiced with hostile references to the revolutionaries as merely politicized philosophes. Barruel argued, in his best-selling Memoirs Illustrating the History of Jacobinism (1797), one of the most widely read books of its period, that the French Revolution was the consequence of a conspiracy of philosophes and freemasons. De Maistre saw the crimes of the Reign of Terror as the apotheosis and the logical consequence of the destructive spirit of the eighteenth century, as well as the divinely decreed punishment for it.

This reaction to the French Revolution did not necessarily extend to its American counterpart. Burke, for one, was entirely supportive of the American Revolution, whose values he saw as compatible with traditions in their best sense.

Religious conservatism

Traditionalism in France

The political Counter-revolution had its counterpart in a religious reaction to its Enlightenment values, especially in France. Félicité Robert de Lamennais (1782-1854) argued that true certitude comes not from individual reason but from the universal consent of reason, which can be seen most clearly in the tradition of the Catholic Church, the largest group of witnesses in the world. Joseph de Maistre, mentioned above as a political counter-revolutionary, was also a staunch defender of the Papacy; in 1819 he wrote Du Pape (On the Pope) in which he argued for the infallible authority of the Pope to bring political stability in Europe.

German fideism

With the long tradition of Lutheranism and Pietism in Germany, a fideist reaction against the Enlightenment emerged there. Johann Georg Hamann (1730-1788) maintained that reason is limited when people try to understand themselves and all existence, and that this limitation of reason leads them to feel that they are ignorant. Consciousness of ignorance leads to genuine faith. Hamann's thought later influenced Søren Kierkegaard, the father of Existentialism. Another German fideist was Friedrich Heinrich Jacobi (1743-1819), who believed that super sensible realities such as God can be perceived by an intuitive feeling or faith, as distinguished from scientific reason.

Romanticism and the Counter-Enlightemment

Rousseau's romantic sentimental longing for nature was an influence for the emergence of a new movement called Romanticism around the end of the eighteenth century and the beginning of the nineteenth century, as an another reaction against the Enlightenment. It was especially in Germany that this movement, with its emphasis upon imagination, spontaneity, and passion, flourished in the fields such as literature and art. Johann Gottfried von Herder (1744-1803), Johann Wolfgang von Goethe (1749-1832), and Friedrich Schlegel (1772-1829) were among the well-known Romantics.

Isaiah Berlin equates this German Romanticism with the so-called "Counter-Enlightenment."^[3] The term "Counter-Enlightenment" was originally coined by German philosopher Friedrich Nietzsche (Gegenaufklärung in German) as he was speaking of it in passing at the end of the nineteenth century, but was popularized by Berlin in the twentieth century. Graeme Garrard identifies Rousseau as the father of the Counter-Enlightenment,^[4] and even broadens the meaning of the term "Counter-Enlightenment," by saying that there have been many Counter-Enlightenments from the middle of the eighteenth century to the twentieth century amongst various critics, both conservative and liberal alike, including postmodernists and feminists.^[5]

Postmodernism

After the end of the Second World War the Enlightenment tradition reemerged as a key organizing concept in social and political thought and the history of ideas. But with the rise of postmodernism, which is one of the Counter-Enlightenments according to Garrard, the features of the Enlightenment started to be regarded as liabilities—excessive specialization, failure to heed traditional wisdom or provide for unintended consequences, and the excessive admiration of Enlightenment figures such as the Founding Fathers of the United States. They prompted a backlash against both science- and Enlightenment-based dogma in general. Postmodern philosophers such as Michel Foucault (1926-1984) are often understood as arguing that the Age of Reason unfairly constructed a vision of unreason as being demonic and subhuman, and therefore, evil and befouling.^[6] Foucault critiques the tendency of the Enlightenment tradition to explain everything according to a dominant mega-theory, so that everything must fit the master-narrative. He saw truth as more subjective and all disciplines as created by elites who control the academy, who determine, often based on self-interests, the standards of normality. Once one method has been selected over others, alternatives become deviant. What does not conform is heresy. History, for example, is written by winners not losers, usually by men not women, by the elite not the workers.

Foucault actually draws some of his ideas from the Freudo-Marxist book written by Max Horkheimer and Theodor Adorno of the Frankfurt School, Dialectic of Enlightenment, which was a penetrating critique of what they perceived as the contradiction of Enlightenment thought: Enlightenment is at once liberatory and, through the domination of instrumental rationality, tending towards totalitarianism, such as fascism, in the twentieth century.^[7] (Tellingly, the book says nothing about communism, which is, for many liberal critics of the Enlightenment like Berlin, directly descended from the rationalism of the philosophes.)

Muslim critique

S. H. Nasr expresses Muslim criticism of the Enlightenment as separating knowledge from value. Western science and technology, he says, is immoral because there is no concern with the consequences of progress, but focus only with progress itself. Science no longer serves humanity, but its own quest for yet more knowledge. His basic critique is that reason became detached from "revelation," and thus also from values.^[8] Other Muslims argue that while Western science, post-Enlightenment, places trust in reason alone, Islamic science places its trust in God's revelation; Western science values science for its own sake, Islamic science regards itself as a type of worship; Western science claims impartiality, Islamic science claims a partiality towards what is true and beneficial for humanity; Western science reduces the world to what can be empirically verified, Islamic science admits the reality of the spiritual dimension.^[9] Of course, such a contrast sets up a caricature of Western science over and against a very ideal view of Islamic science, but it does represent a reasoned critique of post-Enlightenment assumptions. Nasr castigates contemporary Islamic fundamentalists for claiming that when they borrow Western technology that are retrieving what Islam gave Europe through Spain. Nasr argues that the West condemns as heretics the very philosophers from which they borrowed, while Western science also stands on a foundation which they reject, that is, the primary of reason over revelation. There are also Christians who likewise have criticized the Enlightenment.

Critical acceptance

At the end of the eighteenth century, Christian thinkers such as Kant and Friedrich Schleiermacher (1768-1834) were actually appreciative of the Enlightenment, but at the same time, they were of Pietistic background. They were deeply aware of the tension of their Pietistic faith tradition with the humanism of the Enlightenment. So, they attempted to critically accept Enlightenment thought, by synthesizing both traditions. Kant came up with a religion of "practical reason" (not of "pure reason") as a new synthesis of the two, while Schleiermacher decided that "feeling" (not "pure reason" nor "practical reason") is the domain of synthesis. Their projects of synthesis set the tone of nineteenth century Christian theology.

Today, many conservative and evangelical Christians see the Enlightenment tradition as a continued challenge to their faith. The tension of the two traditions still seems to continuously exist today. So, in the twentieth century Reinhold Niebuhr (1892-1971) called for "a new synthesis" of both traditions and Paul Tillich (1886-1965) for "new ways of mediation."^[10] Also, "progressive" evangelicals such as Clark Pinnock, Stanlery J. Glenz, and Alister McGrath have been open to dialogue with the Enlightenment tradition.

Notes

References

ISBN links support NWE through referral fees

• Bennett, Clinton. Muslims and Modernity. NY & London: Continuum, 2005. ISBN 082645481X
• Berlin, Isaiah. "The Counter-Enlightenment," in The Proper Study of Mankind: An Anthology of Essays. Farrar, Straus and Giroux, 2000.
• Bronner, Stephen Eric. Reclaiming the Enlightenment. NY: Columbia University Press, 2004. ISBN 0231126085
• Brown, Stuart, ed. British Philosophy in the Age of Enlightenment. London: Routledge, 2002. ISBN ISBN
• Buchan, James. Crowded with Genius: The Scottish Enlightenment: Edinburgh's Moment of the Mind. NY: HarperCollins Publishers, 2003. ISBN 0060558881
• Cassirer, Ernst et al. The Philosophy of the Enlightenment. Princeton, NJ: Princeton University Press, 1979. ISBN 0691019630
• Foucault, Michel. Madness and Civilization: A History of Insanity in the Age of Reason. Vintage Books, 1988.
• Garrard, Graeme. Counter-Enlightements: From the Eighteenth Century to the Present. Routledge, 2005.
• Garrard, Graeme. Rousseau's Counter-Enlightenment: A Republican Critique of the Philosophes. State University of New York Press, 2003.
• Gay, Peter. The Enlightenment: An Interpretation. NY: W. W. Norton & Company, 1996. ISBN 0704500175
• Herman, Arthur. How the Scots Invented the Modern World: The True Story of how Western Europe's Poorest Nation Created Our World and Everything in It. NY: Crown, 2001. ISBN 0609606352
• Hill, Jonathan. Faith in the Age of Reason. Downers Grove, IL: Lion/Intervarsity Press, 2004. ISBN 0830823603
• Himmelfarb, Gertrude. The Roads to Modernity: The British, French, and American Enlightenments. NY: Knopf: Distributed by Random House,2004. ISBN 1400042364
• Horkheimer, Max, and Theodor Adorno. Dialectic of Enlightenment Translated by Edmund Jephcott. Stanford University Press, 2002.
• Hulluing, Mark. Autocritique of Enlightenment: Rousseau and the Philosophes. Cambridge, MA: Harvard University Press, 1994. ISBN 0674054253
• Jacob, Margaret. Enlightenment: A Brief History with Documents. Boston: Bedford/St. Martin’s, 2000. ISBN 0312237014
• Kors, Alan Charles, ed. Encyclopedia of the Enlightenment. 4 volumes. NY: Oxford: Oxford University Press, 2003.
• Louis Dupre, Louis. The Enlightenment & the Intellectual Foundations of Modern Culture. New Haven, CT: Yale University Press, 2004. ISBN 0300100329
• May, Henry F. The Enlightenment in America. NY: Oxford University Press, 1976. ISBN 0195023676
• McGiffert, Arthur Cushman. Protestant Thought Before Kant. London: Duckworth & Co., 1911.
• Melamed, Yitzhak Y. "Salomon Maimon and the Rise of Spinozism in German Idealism," Journal of the History of Philosophy, Volume 42, Issue 1
• Munck, Thomas. Enlightenment: A Comparative Social History 1721-1794. London: Arnold, 2000. ISBN 034066326X
• Nasr, S. H. Traditional Islam in the Modern World. London: Routledge, 1990. ISBN 0710303327
• Newbigin, Lesslie. Foolishness to the Greeks. Grand Rapids, MI: Eeerdmans, 1986. ISBN 0802801765
• Niebuhr, Reinhold. The Nature and Destiny of Man. Vol. 2: Human Destiny. New York: Charles Scribner's Sons, 1964.
• Tillich, Paul. A History of Christian Thought. New York, Simon and Schuster, 1968.