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EPISTEMOLOGY

EPISTEMOLOGY. Epistemology means "theory of knowledge," and sometimes more specifically "theory of the sciences." As a term, epistemology (French, épistémologie, German, Erkenntnistheorie) entered European languages in the mid-nineteenth century. As a subject matter, it was present in ancient Greece, both in Plato's discussions of knowledge in the Meno and Theaetetus, and in Aristotle's characterizations in his logical works of "scientific" knowledge, that is, knowledge organized around basic principles from which other knowledge can be derived, or through which various facts can be explained. The root word episteme meant 'knowledge' in Greek; in early modern times the corresponding Latin word scientia meant 'organized knowledge', especially of a sort suitable for presentation as an ordered body of doctrine.

In early modern Europe, the theory of knowledge was examined and discussed in a variety of intellectual contexts. These included discussions of the methods and structure of knowledge in general, but especially of organized knowledge. The most important objects of knowledge included God and religious doctrines, the natural world as a whole as well as specific parts of it (as in astronomy, mechanics, or metallurgy), and knowledge of human nature, including the human body (in medicine and physiology) and the soul or mind. These topics were discussed in university courses and the extensive literature they spawned, and in the works of individual philosophers outside universities, perhaps under princely or other wealthy patronage, but often not. European universities were church-related institutions that had been invigorated by the recovery of Aristotle's and other ancient works in the twelfth to sixteenth centuries. They provided a backdrop of theory, largely Aristotelian, of how knowledge is acquired and organized. Significant early modern thinkers such as Nicolaus Copernicus (1473–1543), Johannes Kepler (1571–1630), Galileo Galilei (1564–1642), Francis Bacon (1561–1626), René Descartes (1596–1650), Thomas Hobbes (1588–1679), Baruch Spinoza (1632–1677), Gottfried Wilhelm Leibniz (1646–1716), John Locke (1632–1704), George Berkeley (1685–1753), and David Hume (1711–1776) worked largely outside this setting. Of major early modern philosophers, only Immanuel Kant (1724–1804) enjoyed a career as a university professor.

THE NEW SCIENCE

The single most significant early modern epistemological episode was the rise of the "new science" in the period from 1500 to 1750. This episode is sometimes described as the "scientific revolution," even though it took two hundred and fifty years to unfold and did not really constitute a unified revolution. Early results in astronomy (the Sun-centered solar system) and optics (the theory of lenses) fomented intellectual change and heralded the extension of human knowledge into new domains of the large and the small, through the telescope and microscope. The theory of vision exemplifies themes arising from this initial work. Relying on optical advances, Descartes developed a bold new conception of the physiological and cognitive bases of sight, which challenged Aristotelian orthodoxies concerning the physical and physiological operation of the senses, and formed part of his more general challenge to the Aristotelian theory of mind. In his fully developed system, Descartes appealed to purely rational considerations (epistemological rationalism) to ground his new theory of matter and of sensory properties such as light and color. Berkeley challenged Descartes's theory of vision in developing his own rival theory of knowledge, which denied any purely rational insight into the nature of matter, and rendered sensory experience the sole basis for knowledge of the natural world (epistemological empiricism).

The most epistemologically impressive achievement of the new science was Newton's mechanics, which unified the celestial and terrestrial domains through the laws of motion and the inverse-square law of gravitational attraction. Isaac Newton (1642–1727) claimed that his new advances arose by turning away from rationalist philosophical systems such as that of Descartes (though Newton's work arose partly in direct response to Descartes's physical theories), and relying instead on observation and experiment. Indeed, the inverse-square law was established by fitting a single mathematical law to a diversity of empirical information about falling bodies and planetary motions. Further, Newton did not pretend to understand how gravity works. He simply claimed that bodies tend toward one another according to his law. His scientific achievements inspired subsequent philosophical analysis and were used to support epistemological empiricism.

COGNITION AND PSYCHOLOGY

Early modern theories typically explained the cognitive basis of knowledge through the powers of the human mind. In the Aristotelian scheme, various cognitive powers had been distinguished, including the senses, imagination, memory, and intellect. Later authors accepted these basic powers and focused epistemological debate on their mode of operation, scope, and limits. The intellect and senses were viewed as natural mental tools for the production of knowledge. Thus, the nature and possibility of knowledge might be investigated via the power and reliability of the human cognitive faculties. Rationalist epistemologists such as Descartes, Spinoza, and Leibniz agreed that the human intellect possesses the capacity by itself, without appeal to sensory experience, to discern the essence or nature of God, matter, and the human mind. Empiricist philosophers such as Locke and Hume denied such power to the human intellect, and sought to base all human knowledge of the natural world in sensory experience. Hume held that the human mind differs only in degree from the minds of other animals, and denied that the human cognitive faculties naturally confer rational justification on their products. Knowledge of significant matters of fact for him reduced to cognitive habits produced by experiencing empirical regularities. Kant later created a distinction between the empirical psychological study of the mind (as in Hume), and the study of the logical or conceptual basis of knowledge. In this way he distinguished epistemology as a subject area from empirical psychology (even though he didn't possess the German word for "epistemology").

ORDER AND SYSTEM OF KNOWLEDGE

Early modern philosophers were presented an order of knowledge in university instruction, largely derived from the Aristotelian organization of the disciplines. Knowledge was divided into the theoretical (metaphysical and physical) and the practical (moral and political). Metaphysics studied the nature of being itself (the fundamental nature of reality, such as substance and its properties). Physics included the entire natural world, from the basic properties of bodies or matter through the study of living things (biology) to psychology. The eighteenth century articulated such systems, as in the Encyclopédie of Denis Diderot (1713–1784) and Jean Le Rond d'Alembert (1717–1783), and in the highly structured philosophical system of the German philosopher Christian Wolff (1679–1754). These later systems often agreed with Bacon in dividing knowledge relative to the cognitive faculties: history—which meant all collections of facts, whether about nature or about human society—was based in memory, poetry (and art more generally) was based in imagination, and philosophy—both theoretical, including what we would call natural science, and practical—was based in reason (or the intellect). Such classifications sometimes diverged. Thus, psychology was first classified under physics or the science of nature, later as a metaphysical science, then as a "moral science" (or "human science"), and later again as a natural science. Classification and reclassification of the disciplines continues.

SKEPTICISM AND LIMITS

In many accounts of early modern epistemology, the revival of ancient skepticism in the sixteenth century figures prominently. Skeptical writings did inspire discussion. In religious contexts, skepticism about human ability to understand the divine was used both to support the claim that organized religion must use its divinely sanctioned authority to teach the truth about God and religious topics, and also to challenge whether anyone can claim to have the truth about such matters. Some philosophers, such as Francisco Sánchez (c. 1550–1623), skeptically questioned whether human theoretical knowledge could really uncover the nature of reality as in metaphysics, and suggested a more limited, experience-based goal for knowledge. Descartes used skepticism as a tool for achieving certainty in metaphysical knowledge, but did not himself take the skeptical threat seriously. Other philosophers, such as Spinoza and Locke, quickly dismissed skeptical arguments. Philosophical empiricists such as Hume developed a mitigated skepticism, permitting Newtonian-type knowledge of empirical regularities in nature, but denying human ability to go beyond such regularities to the existence of God or the alleged immateriality of the human soul or mind. Generally, early modern epistemology increasingly recognized limits to human knowledge, culminating in Kant's system of transcendental idealism, according to which knowledge of bare reality, the existence of God, or the soul's immateriality, lie beyond human capacity.

See also Alembert, Jean Le Rond d'; Aristotelianism; Bacon, Francis; Berkeley, George; Cartesianism; Copernicus, Nicolaus; Descartes, René; Diderot, Denis; Empiricism; Encyclopédie; Enlightenment; Galileo Galilei; Hobbes, Thomas; Hume, David; Kant, Immanuel; Kepler, Johannes; Leibniz, Gottfried Wilhelm; Locke, John; Logic; Natural Law; Newton, Isaac; Philosophes; Philosophy; Skepticism: Academic and Pyrrhonian; Spinoza, Baruch; Wolff, Christian.

BIBLIOGRAPHY

Primary Source

Sánchez, Francisco. That Nothing Is Known. Translated by Douglas F. S. Thomson. Cambridge, U.K., and New York, 1988. Translation of Quod Nihil Scitur (1581).

Secondary Sources

Ayers, Michael, and Daniel Garber, eds. Cambridge History of Seventeenth-Century Philosophy. Cambridge, U.K., 1998. Contains chapters on the cognitive faculties and other epistemological topics.

Emmanuel, Steven, ed. The Blackwell Guide to the Modern Philosophers: From Descartes to Nietzsche. Oxford and Malden, Mass., 2001. Contains chapters on all major early modern philosophers, often focusing on epistemology.

Hatfield, Gary. Routledge Philosophy Guidebook to Descartes and the Meditations. London and New York, 2003. Discusses Descartes's epistemology in relation to its intellectual context, including the rise of the new science.

Henry, John. The Scientific Revolution and the Origins of Modern Science. London and New York, 1997. Includes discussion of the philosophical context of the new science.

GARY HATFIELD