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In epistemology and in its modern sense, rationalism is "any view appealing to reason as a source of knowledge or justification".^[1] In more technical terms, it is a method or a theory "in which the criterion of the truth is not sensory but intellectual and deductive".^[2] Different degrees of emphasis on this method or theory lead to a range of rationalist standpoints, from the moderate position "that reason has precedence over other ways of acquiring knowledge" to the more extreme position that reason is "the unique path to knowledge".^[3] Given a pre-modern understanding of reason, rationalism is identical to philosophy, the Socratic life of inquiry, or the zetetic (skeptical) clear interpretation of authority (open to the underlying or essential cause of things as they appear to our sense of certainty). In recent decades, Leo Strauss sought to revive "Classical Political Rationalism" as a discipline that understands the task of reasoning, not as foundational, but as maieutic. Rationalism should not be confused with rationality, nor with rationalization.

In politics, rationalism since the Enlightenment historically emphasized a "politics of reason" centered upon rational choice, utilitarianism, secularism, and irreligion^[4] — the latter aspects' anti-traditionalist and antitheistic elements since partly ameliorated by utilitarian adoption of pluralistic rationalist methods practicable irrespective of particular ideologies.^[5][6]

Background [edit]

Since the Enlightenment, rationalism is usually associated with the introduction of mathematical methods into philosophy, as in Descartes, Leibniz, and Spinoza.^[2] This is commonly called continental rationalism, because it was predominant in the continental schools of Europe, whereas in Britain empiricism dominated.

Rationalism is often contrasted with empiricism. Taken very broadly these views are not mutually exclusive, since a philosopher can be both rationalist and empiricist.^[1] Taken to extremes the empiricist view holds that all ideas come to us through experience, either through the external senses or through such inner sensations as pain and gratification, and thus that knowledge is essentially based on or derived from experience. At issue is the fundamental source of human knowledge, and the proper techniques for verifying what we think we know (see Epistemology).

Proponents of some varieties of rationalism argue that, starting with foundational basic principles, like the axioms of geometry, one could deductively derive the rest of all possible knowledge. The philosophers who held this view most clearly were Baruch Spinoza and Gottfried Leibniz, whose attempts to grapple with the epistemological and metaphysical problems raised by Descartes led to a development of the fundamental approach of rationalism. Both Spinoza and Leibniz asserted that, in principle, all knowledge, including scientific knowledge, could be gained through the use of reason alone, though they both observed that this was not possible in practice for human beings except in specific areas such as mathematics. On the other hand, Leibniz admitted in his book Monadology that "we are all mere Empirics in three fourths of our actions."^[3] Rationalism is predicting and explaining behavior based on logic.^{[clarification needed]}

Philosophical usage [edit]

The distinction between rationalists and empiricists was drawn at a later period, and would not have been recognized by the philosophers involved. Also, the distinction was not as clear-cut as is sometimes suggested; for example, Descartes and Locke have similar views about the nature of human ideas.^[7] The three main rationalists were all committed to the importance of empirical science, and in many respects the empiricists were closer to Descartes in their methods and metaphysical theories than were Spinoza and Leibniz.^{[citation needed]}

History [edit]

René Descartes (1596–1650) [edit]

Descartes thought that only knowledge of eternal truths – including the truths of mathematics, and the epistemological and metaphysical foundations of the sciences – could be attained by reason alone; other knowledge, the knowledge of physics, required experience of the world, aided by the scientific method. He also argued that although dreams appear as real as sense experience, these dreams cannot provide persons with knowledge. Also, since conscious sense experience can be the cause of illusions, then sense experience itself can be doubtable. As a result, Descartes deduced that a rational pursuit of truth should doubt every belief about reality. He elaborated these beliefs in such works as Discourse on Method, Meditations on First Philosophy, and Principles of Philosophy. Descartes developed a method to attain truths according to which nothing that cannot be recognised by the intellect (or reason) can be classified as knowledge. These truths are gained "without any sensory experience", according to Descartes. Truths that are attained by reason are broken down into elements that intuition can grasp, which, through a purely deductive process, will result in clear truths about reality.

Descartes therefore argued, as a result of his method, that reason alone determined knowledge, and that this could be done independently of the senses. For instance, his famous dictum, cogito ergo sum, is a conclusion reached a priori i.e., prior to any kind of experience on the matter. This was, for Descartes, an irrefutable principle upon which to ground all forms of other knowledge. Descartes posited a metaphysical dualism, distinguishing between the substances of the human body ("res extensa") and the mind or soul ("res cogitans"). This crucial distinction would be left unresolved and lead to what is known as the mind-body problem, since the two substances in the Cartesian system are independent of each other and irreducible.

Baruch Spinoza (1632–1677) [edit]

The philosophy of Baruch Spinoza is a systematic, logical, rational philosophy developed in seventeenth-century Europe.^[8][9][10] Spinoza's philosophy is a system of ideas constructed upon basic building blocks with an internal consistency with which Spinoza tried to answer life's major questions and in which he proposed that "God exists only philosophically."^[10][11] He was heavily influenced by thinkers such as Descartes,^[12] Euclid^[11] and Thomas Hobbes,^[12] as well as theologians in the Jewish philosophical tradition such as Maimonides.^[12] But his work was in many respects a departure from the Judeo-Christian tradition. Many of Spinoza's ideas continue to vex thinkers today and many of his principles, particularly regarding the emotions, have implications for modern approaches to psychology. Even top thinkers have found Spinoza's "geometrical method"^[10] difficult to comprehend: Goethe admitted that he "could not really understand what Spinoza was on about most of the time."^[10] His magnum opus, Ethics, contains unresolved obscurities and has a forbidding mathematical structure modeled on Euclid's geometry.^[11] Spinoza's philosophy attracted believers such as Albert Einstein^[13] and much intellectual attention.^{[14][15][16][17][18]}

Gottfried Leibniz (1646–1716) [edit]

Leibniz was the last of the great Rationalists who contributed heavily to other fields such as mathematics. He did not develop his system, however, independently of these advances. Leibniz rejected Cartesian dualism and denied the existence of a material world. In Leibniz's view there are infinitely many simple substances, which he called "monads" (possibly taking the term from the work of Anne Conway).

Leibniz developed his theory of monads in response to both Descartes and Spinoza. In rejecting this response he was forced to arrive at his own solution. Monads are the fundamental unit of reality, according to Leibniz, constituting both inanimate and animate things. These units of reality represent the universe, though they are not subject to the laws of causality or space (which he called "well-founded phenomena"). Leibniz, therefore, introduced his principle of pre-established harmony to account for apparent causality in the world.

Immanuel Kant (1724–1804) [edit]

Immanuel Kant started as a traditional rationalist, having studied the rationalists Leibniz and Wolff, but after studying David Hume's works, which "awoke [him] from [his] dogmatic slumbers", he developed a distinctive and very influential rationalism of his own, which attempted to synthesize the traditional rationalist and empiricist traditions.

Kant named his branch of epistemology Transcendental Idealism, and he first laid out these views in his famous work The Critique of Pure Reason. In it he argued that there were fundamental problems with both rationalist and empiricist dogma. To the rationalists he argued, broadly, that pure reason is flawed when it goes beyond its limits and claims to know those things that are necessarily beyond the realm of all possible experience: the existence of God, free will, and the immortality of the human soul. Kant referred to these objects as "The Thing in Itself" and goes on to argue that their status as objects beyond all possible experience by definition means we cannot know them. To the empiricist he argued that while it is correct that experience is fundamentally necessary for human knowledge, reason is necessary for processing that experience into coherent thought. He therefore concludes that both reason and experience are necessary for human knowledge.

See also [edit]

References [edit]

Primary sources

• Descartes, René (1637), Discourse on Method.
• Spinoza, Baruch (1677), Ethics.
• Leibniz, Gottfried (1714), Monadology.
• Kant, Immanuel, (1781/1787), Critique of Pure Reason.

Secondary sources

• Audi, Robert (ed., 1999), The Cambridge Dictionary of Philosophy, Cambridge University Press, Cambridge, UK, 1995. 2nd edition, 1999.
• Blackburn, Simon (1996), The Oxford Dictionary of Philosophy, Oxford University Press, Oxford, UK, 1994. Paperback edition with new Chronology, 1996.
• Bourke, Vernon J. (1962), "Rationalism", p. 263 in Runes (1962).
• Fischer, Louis (1997). The Life of Mahatma Gandhi. Harper Collins. pp. 306–307. ISBN 0-00-638887-6. 
• Lacey, A.R. (1996), A Dictionary of Philosophy, 1st edition, Routledge and Kegan Paul, 1976. 2nd edition, 1986. 3rd edition, Routledge, London, UK, 1996.
• Runes, Dagobert D. (ed., 1962), Dictionary of Philosophy, Littlefield, Adams, and Company, Totowa, NJ.
• Baird, Forrest E.; Walter Kaufmann (2008). From Plato to Derrida. Upper Saddle River, New Jersey: Pearson Prentice Hall. ISBN 0-13-158591-6. 

External links [edit]

• Rationalism vs. Empiricism entry in the Stanford Encyclopedia of Philosophy
• Rationalism at PhilPapers
• Rationalism at the Indiana Philosophy Ontology Project
• Continental Rationalism entry by Thomas M. Lennon and Shannon Dea in the Stanford Encyclopedia of Philosophy
• Markie, Peter (2004), "Rationalism vs. Empiricism", Stanford Encyclopedia of Philosophy, Edward N. Zalta (ed.),
• John F. Hurst (1867), History of Rationalism Embracing a Survey of the Present State of Protestant Theology