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PHILOSOPHY

PHILOSOPHY. In the sixteenth century, "philosophy" still meant Aristotelianism in its medieval Christian form, with Platonism and other ancient doctrines, including stoicism, Epicureanism, skepticism, eclecticism, and various occult traditions, remaining on the academic margins, though they were becoming lively topics of intellectual controversy. Philosophical practice of the period was increasingly devoted to the comparative study of these systems. Opposing these dogmatic (or skeptical) traditions, however, was the novel and unorthodox question posed by Tommaso Campanella (1568–1639), "whether it is useful for Christian philosophy to construct a new philosophy after that of the pagans, and if so, on what grounds." This was a challenge taken up by a number of fifteenth-, sixteenth-, and seventeenth-century thinkers, including Marsilio Ficino, Pico della Mirandola, and other Neoplatonists; Lorenzo Valla, Desiderius Erasmus, and other humanists; Rudolphus Agricola, Petrus Ramus, and other reformers of rhetoric and logic; Jacopo Zabarella, Giordano Bruno, and other Italian natural philosophers; and Francis Bacon, Johannes Kepler, Galileo Galilei, René Descartes, Isaac Newton, and other champions of the "party of nature" and a self-proclaimed "new philosophy."

The study of these and other philosophical movements beyond the academic mainstream has been pursued in the past two generations, especially by Paul Oskar Kristeller and his students. This has opened up new perspectives on the history of Western thought, even though the older traditions—which tend to jump from the medieval theologian-philosopher Thomas Aquinas (1224/1225–1274) and Scholasticism directly to Descartes (1596–1650), the French rationalist and metaphysician, and other seventeenth-century system builders—have remained dominant in the modern philosophical canon.

THE BREAK WITH SCHOLASTIC PHILOSOPHY

According to convention, modern philosophy begins with Descartes and the English empiricist and philosopher of science Francis Bacon (1561–1626), pivotal figures who broke decisively with the intellectual system of the late medieval world and helped to articulate a new agenda for philosophy. This simplifies a complex story, as medieval philosophy gave way to early modern systems of thought slowly, across several generations. But Bacon and Descartes indeed helped to usher in a revolutionary period in philosophy, with upheavals in crucial areas such as epistemology, metaphysics, philosophy of science, ethics, and political philosophy.

At the start of the seventeenth century, the presumptive authority of time-tested ancient thinkers, particularly the towering figure of Aristotle (384–322 B.C.E.), still carried great weight in philosophy and the sciences. The overwhelmingly dominant philosophical system, firmly entrenched in the universities, was Aristotelian Scholasticism, a synthesis of Aristotle's philosophy with Christian doctrine that had been forged by Aquinas. But modern philosophers such as Bacon and Descartes rejected this traditional deference toward Aristotle and other ancient figures of authority and broke with the Scholastic system. The decline in respect for traditional philosophical authorities had various sources. The religious crises of the Reformation and Counter-Reformation had shaken the presumption in favor of tradition, opening space for a more assertive questioning of received doctrine. Humanist scholars had unearthed and reintroduced lost systems of thought, such as ancient Greek atomism and classical skepticism, that presented alternatives to the theories of Aristotle, encouraging critical debate on the merits of all these competing systems. Developments in Renaissance science and the burgeoning scientific revolution were also exposing the fallibility of Aristotelian physics and cosmology. While Scholastic philosophy continued to dominate the universities through the seventeenth century, the main developments in modern philosophy came from thinkers operating outside of this old establishment, usually men of independent means or supported by aristocratic patronage rather than a professor's salary. These philosophers typically addressed their works to the educated classes more broadly and wrote in the vernacular rather than the Latin of Scholastic academia.

In practice the break with the Scholastic intellectual system helped to reestablish philosophy as an autonomous discipline outside of theology. While most of the leading early modern philosophers were religious believers who sought to develop philosophical theories consistent with their religious commitments, nevertheless there was a marked shift toward the scientific study of human nature and the physical world, unmediated by an explicit emphasis on theological doctrine. The trend toward secularization encompassed even ethics and political philosophy, with philosophers such as Thomas Hobbes (1588–1679), David Hume (1711–1776), and Immanuel Kant (1724–1804) founding moral and political principles on reason or human nature, rather than the commands of God. (This "secularization thesis" is also part of the conventional story of modern philosophy, but it has been challenged by some recent scholars, most notably Hans Blumenberg.)

ASSOCIATION WITH THE NEW SCIENCE

The agenda of early modern philosophy was closely connected with the new scientific worldview pioneered by figures such as Galileo (1564–1642), Kepler (1571–1630), and Newton (1642–1727). Bacon, Descartes, and the philosophers who followed them were gripped by the explanatory range and power of the new science and were concerned to articulate, codify, and defend its methods and to explore its implications for metaphysics and epistemology. Several philosophers of the period were involved firsthand in the practice of science: leading examples include Descartes and the German philosophers Gottfried Wilhelm Leibniz (1646–1716) and Kant. Early modern philosophers would also self-consciously import the experimental method of the new science into the realm of philosophy, as in the theories of mind developed by the British empiricists John Locke (1632–1704) and Hume.

The new scientific worldview brought a fresh range of philosophical questions to the fore. First, there were questions concerning scientific method (a particular interest of Bacon, Locke, and Hume). How could inductive extrapolation from observed phenomena to unobserved cases be justified? Would science ever show us the inner essence of things and explain their underlying causal powers, or was it limited to merely cataloging correlations and patterns among surface phenomena? Then there were the metaphysical questions. What did the success of the new mathematical, quantitative models of nature show us about the relationship between mathematics on the one hand and empirical reality on the other? In what sense were subjective features of experience like colors and sounds part of the material world? And, most pressingly, what was the status of human beings in the scientific world picture? Was there still room for free will, morality, religion, and the human soul in the vast, cold, deterministic world of the new mathematical sciences?

EPISTEMOLOGY

Early modern philosophy is justly famous for its reorientation toward epistemology, or the theory of knowledge. The examination of the processes by which we arrive at and justify knowledge claims took on a new primacy in the period, as philosophers such as Bacon, Descartes, Locke, Hume, and Kant each in their own way urged the importance of clarifying the nature and limits of our own cognitive faculties. Apart from the general wisdom of examining the sources and justifiability of our beliefs before boldly advancing theories on subjects that may exceed our capacities, the new emphasis on epistemology had several more immediate motivations. It was connected to the collapse in the prestige of traditional sources of authority such as Aristotle and church doctrine. If ancient authorities no longer commanded automatic deference, then who—or what—should a responsible thinker take as a legitimate source of knowledge? It was also related to the questions of method and scientific procedure raised by the achievements of the new science. Most famously, it was prompted by the skeptical onslaught of figures like Michel de Montaigne (1533–1592), the great French essayist and popularizer of ancient forms of skepticism, who argued that all the bases of our so-called knowledge are inadequate.

It is customary to distinguish between two main factions in early modern epistemology: the empiricists on the one hand and the rationalists on the other. The distinction can be overemphasized at the risk of falsely caricaturing the rationalists as hostile to empirical investigation, or of obscuring a complex pattern of intellectual influences back and forth between the two groups. Nevertheless the distinction does capture an important difference in approaches to the theory of knowledge. The empiricists—led by Bacon, Locke, and Hume—argued that all our ideas are ultimately acquired in experience, and that the limits of experience set boundaries on our knowledge. The empiricist thus counsels a certain humility: our knowledge is forever limited to the patterns and regularities we witness among the empirically observable features of the world; metaphysical speculation about the inner nature of things transcends our capacities. By contrast, the rationalists—led by Descartes, the Dutch Jewish metaphysician Baruch Spinoza (1632–1677), and Leibniz—argued that our minds are innately furnished with certain ideas over and above those we acquire in experience. Using these innate ideas we can reason about things transcending experience. For the rationalist, this explains how we can have knowledge that goes beyond all possible empirical confirmation, either because of its universal nature (logic, mathematics, knowledge of the laws of nature) or because of its transcendent subject matter (God, the soul, morality).

METAPHYSICS

Early modern philosophers explored a wide range of issues in metaphysics (the study of the ultimate nature of reality), including, notably, problems of space and time, causation, the ultimate structure of matter, the nature of morality, and God. However, the most characteristic metaphysical questions of the period focus on the connection between the human mind or soul on the one hand and the physical world on the other. Clearly these issues were related to the epistemological turn, and in particular to Descartes's famous skeptical problem of how we can know that there is a physical realm beyond our minds at all. But such questions were also forced by reflection on the new scientific worldview. Advocates of the new science such as Galileo and Descartes argued that the objective, mind-independent world described by science could be exhaustively characterized in terms of mathematically tractable "primary" qualities such as shape, size, and motion. "Secondary" qualities such as colors, tastes, sounds, and smells were then downgraded to a derivative status and were in some sense observer-relative and mind-dependent, more a feature of subjective experience than ultimate objective reality. This distinction had great appeal for most early moderns, but it would be challenged by figures such as the Irish cleric George Berkeley (1685–1753), Hume, and Kant, who pointed out that a clear distinction between mind-dependent and mind-independent properties is not so easy to draw. Kant argued that even space and time were mind-dependent or "ideal." For Berkeley the notion of any mind-independent reality whatsoever was fundamentally incoherent: all that exists are minds and their ideas.

Granted the existence of an objective material realm, the next question concerned the relationship between the mind and the physical body. Descartes developed the popular theory that the mind is an immaterial soul-substance over and above the material brain, arguing that this helped to explain the existence of consciousness and made room both for an afterlife beyond bodily death and for free will (as well as moral responsibility) outside the deterministic laws governing the material order. But others thought the theory raised more problems than it solved, including difficulties in accounting for the causal interaction between immaterial soul and material body. Materialists such as Hobbes and Spinoza insisted that the human animal, mind included, was just a complex material system; others such as Locke counseled a metaphysical agnosticism about the ultimate nature of the thinking self.

POLITICAL PHILOSOPHY

The medieval church and the Scholastic tradition had located the source of political legitimacy in implicit divine approval of established dynasties, a conservative doctrine that left little room for individual rights against the monarch or for systems of popular sovereignty. Leading Protestant theologians such as Martin Luther (1483–1546) reaffirmed the doctrine of divine right, although some of the more radical Anabaptist reformers preached against it. The main philosophical revolt against this medieval tradition came with the social contract theorists: the Dutch legal scholar and philosopher Hugo Grotius (1583–1645), Hobbes, Locke, and the Swiss-born social theorist Jean-Jacques Rousseau (1712–1778). These figures posited a hypothetical "state of nature" without government to explore the basic rights of the individual, and they argued that legitimate state authority was ultimately derived from such foundational individual rights, transferred conditionally through popular (though perhaps implicit) consent. The corollary was that individuals retained certain inalienable rights against government, that state authority was in some (perhaps quite attenuated) sense contingent on popular consent, and that regimes in breach of the implicit contract were illegitimate and could be justly overthrown. Locke would extend the contract theory to argue for religious toleration (although Catholics and atheists were excluded as beyond the pale) on the basis of natural rights, adding arguments premised on general empiricist epistemic humility and on the involuntary nature of religious belief. Conservatives such as Hume and Edmund Burke (1729–1797) attacked the contract theory, arguing that there was in fact no popular consent; the foundation of natural rights was metaphysically dubious; and the doctrine threatened to destabilize the ancient political settlements that secured peace and civic order.

In the international arena the Florentine diplomat and political theorist Niccolò Machiavelli (1469–1527) notoriously endorsed realism, the harsh doctrine that there are no moral constraints governing relations between distinct states. Here he was followed by Hobbes, a skeptic about political morality in the absence of an overarching sovereign power to coercively enforce duties. Opponents of realism included Grotius, who developed a substantial system of international law and moral precepts on the basis of treaty, and Kant, who argued that reason prescribed a universal political morality transcending national jurisdictions and advocated the creation of a "league of nations" to enforce international law.

See also Aristotelianism; Bacon, Francis; Berkeley, George; Bruno, Giordano; Burke, Edmund; Descartes, René; Empiricism; Enlightenment; Epistemology; Erasmus, Desiderius; Free Will; Galileo Galilei; Grotius, Hugo; Hobbes, Thomas; Hume, David; Idealism; Kant, Immanuel; Kepler, Johannes; Leibniz, Gottfried Wilhelm; Locke, John; Logic; Machiavelli, Niccolò; Montaigne, Michel de; Moral Philosophy and Ethics; Nature; Neoplatonism; Newton, Isaac; Political Philosophy; Ramus, Petrus; Renaissance; Rousseau, Jean-Jacques; Scholasticism; Scientific Revolution; Skepticism, Academic and Pyrrhonian; Spinoza, Baruch; Stoicism.

BIBLIOGRAPHY

Primary Sources

Bacon, Francis. Selected Philosophical Works. Edited by Rose-Mary Sargent. Indianapolis, 1999.

Berkeley, George. Three Dialogues Between Hylas and Philonous. Edited by Jonathan Dancy. Oxford and New York, 1998.

——. A Treatise Concerning the Principle of Human Knowledge. Edited by Jonathan Dancy. Oxford and New York, 1997.

Descartes, René. Selected Philosophical Writings. Translated by John Cottingham, Robert Stoothoff, and Dugald Murdoch. Cambridge, U.K., 1988.

Hume, David. An Enquiry Concerning Human Understanding. Edited by Tom L. Beauchamp. Oxford and New York, 1999.

——. An Enquiry Concerning the Principles of Morals. Edited by Tom L. Beauchamp. Oxford and New York, 1998.

Kant, Immanuel. Critique of Pure Reason. Translated by Werner S. Pluhar. Indianapolis, 1996. Translation of Kritik der reinen Vernuft (1781/1787).

——. Ethical Philosophy: The Complete Texts of Grounding for the Metaphysics of Morals and Metaphysical Principles of Virtue, Part II of the Metaphysics of Morals. Translated by James W. Ellington. Indianapolis, 1993. Includes a translation of Grundlegung zur Metaphysik der Sitten (1785).

Leibniz, Gottfried Wilhelm. Philosophical Essays. Translated and edited by Roger Ariew and Daniel Garber. Indianapolis, 1989.

Locke, John. An Essay Concerning Human Understanding. Edited by Peter H. Nidditch. Oxford, 1975.

Spinoza, Baruch. A Spinoza Reader. Edited and translated by Edwin Curley. Princeton, 1994.

Secondary Sources

Ayers, Michael, and Daniel Garber, eds. The Cambridge History of Seventeenth-Century Philosophy. Cambridge, U.K., and New York, 1998. This collection of essays supplies impressive historical detail and covers many neglected figures from the period. It is extremely helpful for those already fairly familiar with the outlines of early modern philosophy, but perhaps a little overwhelming for the beginner.

Blumenberg, Hans. The Legitimacy of the Modern Age. Translated by Robert M. Wallace. Cambridge, Mass., 1983.

Chappell, Vere, ed. The Cambridge Companion to Locke. Cambridge, U.K., and New York, 1994.

Copleston, Frederick. A History of Philosophy. 9 vols. New York, 1953–1963. Superseded in parts by recent scholarship, but still a classic survey. Volume 3 covers the Renaissance up to Bacon; volume 4 covers the rationalists Descartes, Spinoza, and Leibniz; volume 5 covers the British empiricists from Hobbes through Hume; and volume 6 covers the French Enlightenment and Kant.

Cottingham, John, ed. The Cambridge Companion to Descartes. Cambridge, U.K., and New York, 1992.

Cropsey, Joseph, and Leo Strauss, eds. History of Political Philosophy. 3rd ed. Chicago, 1987.

Garrett, Don, ed. The Cambridge Companion to Spinoza. Cambridge, U.K., and New York, 1996.

Guyer, Paul, ed. The Cambridge Companion to Kant. Cambridge, U.K., and New York, 1992.

Jolley, Nicholas. Locke: His Philosophical Thought. Oxford and New York, 1999.

Loeb, Louis E. From Descartes to Hume: Continental Metaphysics and the Development of Modern Philosophy. Ithaca, N.Y., 1981. Presupposing some basic knowledge of standard approaches to the history of early modern philosophy, Loeb criticizes the traditional distinction drawn between the rationalists and the empiricists.

Norton, David Fate, ed. The Cambridge Companion to Hume. Cambridge, U.K., and New York, 1993.

THOMAS HOLDEN