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Rationalism comes in various versions and makes wider or narrower claims. The idea underlying most versions is that reason is the most characteristic faculty of Homo sapiens. Appeal to reason is part of traditional wisdom, yet traditional (ancient Greek) rationalism includes an out of hand dismissal of traditional wisdom. The modern version of this dismissal is the radical demand for starting afresh (Enlightenment radicalism) and admitting only ideas that are proven, absolutely certain, and fully justified by rigorous proof. Science begins with rejecting all doubtful ideas. Francis Bacon initiated the idea that traditional unfounded views are the causes of all error; René Descartes tried to ignore all doubtful ideas and start afresh from nothing. David Hume began his investigations in efforts to delineate all that is certain while ignoring all else; he and many others, from Denis Diderot to Pierre Simon de Laplace, took it for granted that Isaac Newtons success was due to his adherence to Bacons advice. Auguste Comte and T. H. Huxley took it for granted that other fields will be as successful if they only jettison tradition more fully; Ludwig Wittgenstein went further and said only scientific assertions are grammatical (positivism, scientism).


Yet what proof is no one knew. Mathematics was the paradigm of proof, and the success of physics was largely ascribed to its use of mathematical methods, a practice for all to emulate. What is that method, and how can it be applied to the social domain? How does the relinquishing of tradition help word theories mathematically? This was unclear even after the discipline of statistics was developed enough to become applicable to some social studies (as in the work of Adolphe Quételet, 1796-1874). Yet clearly as usefulness gives rational thought its initial (even if not final) worth, at least the rationality of action is obvious: its goal-directedness. Hence the study of rationality is vital for the study of the rational action that is the heart of the study of humanity. Whereas students of nature seldom pay attention to the rationality and the scientific character of their studies, students of humanities are engrossed in them. And whatever their views on this rationality, at least they openly center on it. Thus in the opening of his classic An Inquiry into the Nature and Causes of the Wealth of Nations (1776), Adam Smith declares his intent to ignore irrationality, no matter how widespread it is. Slavery is widespread, yet everyone knows that putting a worker in chains is no incentive, he observed.

The Enlightenment movement deemed Smiths argument obvious; this led to its dismissal of human history as the sad story of needless pain caused by ignorance and superstition. This was an error. The advocacy of the abolition of slavery came in total disregard for its immediate impact on the lot of slave owners. Smith spoke of rationality in the abstract. Because high productivity depends on the division of labor and because this division leads to trade, freedom is efficient. Selfish conduct is rational as long as it is scientific, that is, undogmatic. Life in the light of reason is egalitarian, simple, and happy. This abstract reasoning led to concrete results, including the French Revolution and its terror and wars. Edmund Burke and Georg Wilhelm Friedrich Hegel blamed the radicalism of the revolution for its deterioration into terror. The reaction to the French Revolution was aggressively hostile to radicalism, to egalitarianism, and even to reason (Hegel).


Karl Marx wedded the two great modern movements, the radical Enlightenment movement and the Romantic reaction to it. The former had the right vision, and the latter had the historically right view of the obstacle to its realization. Smith-style harmony between individual and society has no place in traditional society. Hence the institution of enlightened equality is an essential precondition for it. The realization of the radical dream of harmony requires civil war. But it is certainly realizable, he insisted.

Marxs critique of radicalism from within is as popular as ever. We are chained to our social conditions, and rationalism cannot break them. Max Weber, the author of the most popular alternative to Marxs ideas, stressed this; so do all the popular radical critics of the ills of modern (bourgeois) society, chiefly imperialism, racism, and sexism, perhaps also alienation from work. These critics puzzle the uninitiated, as they seem to belabor condemnations of obviously indefensible aspects of modern society. But they do something else; they advance a thesis. Social evils will not go away by sheer mental exercises. Are there any reasonable people who disagree with this thesis? It is hard to say. Perhaps some thinkers still follow the central thesis of the Enlightenment movement. If such people do exist (as seems true but not obviously so), then they are the neoliberals, the Chicago school of economics, which is not confined to economics, as it preaches the idea that a world with free markets still is the best of all possible worlds, even though it is far from ideal (Friedrich A. von Hayek).


What then is rationalism? Of the alternative views on reason, which can count as variants of rationalism? Consider pragmatism, the view of the useful as the true (Hegel, William James, John Dewey). It is unsatisfactory, because assessments of usefulness may be true or not; but is it a version of rationalism? Consider the traditionalist reliance on the test of time (ordinary-language philosophy; neo-Thomism). The assessment of the relative worth of traditions may be cultural (Martin Buber, Amitai Ezioni; communitarianism) or intellectual (Michael Polanyi, Thomas S. Kuhn; postcriticalism). It is unsatisfactory, as these assessments may be true or not; but is it a version of rationalism? There is no telling. The same holds for appeals to other criteria for truth. These are common sense (Hume, Smith, Thomas Reid, Adam Ferguson, George Edward Moore), the intuitions of Great Men (Johann Gottlieb Fichte, Hegel, Martin Heidegger), higher religious sentiments (Friedrich Schleiermacher, Fyodor Dostoevsky, Leo Tolstoy), and superior tastes (Richard Rorty). Are these variants of rationalism? Do they lead to more reasonable human conduct? The standard claim is that their asset is in their ability to maintain social stability. But in the early twenty-first century stability is unattainable and even deemed inferior to democratic controls (Karl R. Popper).

There is no consensus about whether the counsel to limit reason and admit religion is rationalism proper (Moses Maimonides, Saint Thomas Aquinas, Robert Boyle, Moses Mendelssohn, Polanyi) or not (Immanuel Kant, David Strauss, Ludwig Feuerbach, Sigmund Freud, Bertrand Russell, Adolf Grünbaum). The only consensus is about the defiance of reason (Søren Kierkegaard, Max Stirner, Joseph Arthur Comte de Gobineau, Georges Sorel, Friedrich Nietzsche, D. H. Lawrence, Heidegger, perhaps also Paul Feyerabend). The only generally admitted necessary condition for rationalism is the demand to side with reason. Therefore it is fashionable to limit rationalism by allowing the taking of a single axiom on faith while otherwise swearing allegiance to reason (Polanyi, Richard H. Popkin, Pope John Paul II; fideism). The default view should then be that this allegiance suffices. Add to this the consensus around a necessary condition for this allegiance. It is the critical attitude, openness to criticism, the readiness to admit the success of the criticism of any given view. Consider the view that the critical attitude is sufficient as the default option (Popper) and seek valid criticism of it that may lead to its modification, to the admission of some unavoidable limitations on reason, whether in the spirit of Marx or in that of his critics. The need for this limitation comes from purely philosophical considerations. Hume said that we need induction for knowledge and for practice, yet it is not rational (it has no basis in logic); instead, we rely on it out of habit and necessity and this is the best we can do. A popular variant of this is that because induction is necessary, it is in no need of justification (Kant, Russell). Another variant takes it on faith (Polanyi, Popkin; fideism). Is induction really necessary?

This question is welcome. Since finding alternative answers to a worthy question improves their assessment, they are all worthy. Hence all versions of limited rationalism are welcomeas hypotheses to investigate (Salomon Maimon, Popper). This is the power of the method of always trying out the minimal solution as the default.


Critical rationalism is revolutionary because it replaces proof with test; it replaces radical, wholesale dismissal of ideas with the readiness to test piecemeal (Albert Einstein, Popper; reformism). The demand to prove thus yields to the critical attitude (William Warren Bartley III, Willard Van Orman Quine; non-justificationism), recognizing that theories possess graded merit (Einstein, Leonard Nelson, Popper; critical rationalism)by whatever rule we happen to follow, no matter how tentative. Rules are then hopefully improvable (Charles Sanders Peirce, Russell, Popper; fallibilism). Hence diverse rules may serve as competing criteria or as complementary. Being minimalist, critical rationalism invites considering some older theologians as allies, although not their contemporary followers. Unlike radical rationalism, critical rationalism is historically oriented. (It is the view of rationality as relative to contexts and of truth as absolute, as a guiding principle à la Kant.)

This invites critical rationalism to enlist rational thought as a category of rational action (Ian C. Jarvie and Joseph Agassi). And this in turn invites the study of rationalism as an aspect of extant scientific research. It also invites comparison of the various versions of rationalism as to the degree of their adequacy to this task: take scientific research as it is, warts and all, and examine its merits and defects according to the diverse alternatives. This attitude is new and expressed in various studies of the sociology of science, so-called, that often spread over diverse disciplines, including political science and even criminology no less. This renders a part of the project of rationalism the assessments of the intellectual value of the outcome of research, theoretical, practical, or culturalor even aesthetic. The only intellectual justification of a scientific theory, said Einstein, is its ability to explain; its best reward is its successors admission of it as approximate. In this way he stressed that the aim of research is to explain in the hope of approximating the truth. This is open to debate. Social science as a whole may serve as a test case, with the sociology of science at the center of the debate on this matter.

Historically, rationalism doggedly accompanied studies of nature, not social studies. What in these should rationalism approve of? Discussion of this question allowed rationalism to inform the social sciences. A conspicuous example is the vagueness in social studies of the boundaries between philosophy, science, and practice that still invites open discussion. Anything less is below the minimal criterion of the critical attitude.

Critics of minimal rationalism find criticism insufficient, since positive criteria of choice need justification. If so, then rationalism is back to square one. If not, then positive criteria must be tentative, and the issue must shift from their justification to efforts at their improvement. Some do not like this, as it rests on their initial choice that was too arbitrary. They prefer to return to the initial criterion and replace it with the least arbitrary one. They are radicals. The clash is thus between the radical and the critical version of rationalismas well as between them and fideism.

The agenda of rationalismin philosophy, in science, or in practiceis the same: heightening the critical attitude, seeking improvement through criticism everywhere. Where is the starting point? How are we to decide on our agenda? Parliamentary steering committees decide on agendas. The commonwealth of learning, however, is its own steering committee. Those concerned to promote rationalism should do their best to put discussions of it high on the public agenda.


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Joseph Agassi

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In the final section of the Critique of Pure Reason, Immanuel Kant distinguishes empiricism and rationalism:

In respect of the origin of the modes of "knowledge through pure reason," the question is as to whether they are derived from experience, or whether in independence of experience they have their origin in reason. Aristotle may be regarded as the chief of the empiricists, and Plato as the chief of the noologists [rationalists]. Locke, who in modern times followed Aristotle, and Leibniz, who followed Plato have not been able to bring this conflict to any definitive conclusion. [Kemp Smith, trans.]

Kant's vision of a conflict between empiricism and rationalism remains to this day the organizing principle for discussions of early modern metaphysics and epistemology. Kant may have overstated the extent to which there was a conflict between empiricists and rationalists: it has recently been suggested that both may be seen as pursuing the common project of defining the scope and limits of human knowledge. It has also been charged that the very distinction between empiricism and rationalism should be rejected. I believe that the distinction usefully captures certain defining features of early modern philosophy and that the terms rationalism and empiricism should be retained.

Rationalism Defined

Kant's characterization of rationalism is generally accurate. One addition must be made. Like most early modern philosophers, the rationalists conceived of the human cognitive faculties as distinguished into the pure intellect, the senses, and the imagination. The pure intellect was the faculty that enabled human beings to gain knowledge. Rationalism may be defined as the view that substantive truths about the nature of reality may be derived from the pure intellect alone, operating independently of the imagination and the senses.

The Roots of Rationalism

It was by no means idiosyncratic for Kant to take Plato and Aristotle as prefiguring the opposition between rationalism and empiricism; this opposition is, for example, the organizing principle of Raphael's Vatican fresco The School of Athens. Plato points up, to the realm of Forms, the unchanging objects of the pure intellect; Aristotle points to the earth, thereby indicating the experiential origin of knowledge. Plato's commitment to the existence of unchanging truths, sharply contrasted with the variable images of the senses, marks him as the grandfather of early modern rationalism.

Approximately five hundred years later, Saint Augustine synthesized Plato's philosophy with the Christian religion in order to provide the latter a philosophical underpinning. Augustine found in Plato a remedy for the vagaries of sense experience that threatened the truth of Christianity; his work remained seminal for the early modern rationalists: Descartes, Leibniz, and Malebranche, believers all, explicitly hearkened back to Augustine. Aristotle's work, however, held its importance for medieval philosophers. He became known as "the Philosopher," and his thought, especially as interpreted by Aquinas, became the official philosophy of Christianity.

René Descartes

Descartes formulated his conception of philosophy in explicit opposition to the Scholastic Aristotelians' emphasis on sense-based experience. The Meditations are best understood as a series of cognitive exercises that train the meditator to discover truths about the world by the use of pure intellect, independent of the senses. Beginning by purging the self of intellectual preconceptions, by doubting all knowledge hitherto received through the senses, the meditator rebuilds knowledge, achieving clear and distinct ideas of the nature of the soul, God, and body.

The Meditations was not a complete system of philosophy; it only laid the foundation for Descartes's broader philosophical project. Descartes explains in a letter to his friend Marin Mersenne that "my little book on metaphysics contains all the foundations of my physics." The point of the Meditations was to reconceptualize the physical world as a realm of extension, governed by laws of motion, and therefore amenable to mathematical investigation. Descartes envisioned his physics very broadly, extending his view from celestial bodies to terrestrial bodies, the operations of animals, and the nature of the human being. He meant for his scientific project to culminate in the Principles of Philosophy, which remained unfinished, although the broad lines of Cartesian science may be derived from other works.

Although Descartes turned to philosophy (metaphysics) in order to ground science and thought that the only genuine knowledge that human beings could achieve derived from the intellect operating independently of the senses, he nevertheless retained an important place in science for the senses. General truths about body only specify the possible range of explanations of physical phenomena; in order to determine the particular explanations, one must appeal to sense experience. Cartesian rationalism remains limited to the most general truths about the universe.

Benedict Spinoza

Spinoza is the only Jewish thinker among the rationalists. He was excommunicated from the Jewish community of Amsterdam, possibly on account of the heretical views that he held about the nature of God and the immortality of the soul, views later elaborated in his great systematic work, the Ethics. Spinoza's philosophical system is the purest example of rationalism.

Other rationalists remained committed to the truths of revealed religion; Spinoza maintains that the Bible does not contain the word of God, but is a work of men that serves the sociopolitical ends of establishing and securing the commonwealth. In his Theological-Political Treatise, Spinoza therefore argues that human beings should be free to hold whatever religious views they like, provided they do not upset the established civil order.

This work is a prolegomenon to the Ethics, where, on the basis of reason alone, Spinoza radically reconfigures traditional notions of God, nature, and morality. Rejecting all sensory inputs as mere "random experience" that do not reveal the nature of the world, he says there is only one substance, which he strikingly calls "God or nature." All existing things must be understood to be merely modifications of that single substance, not substances in their own right. One of the most provocative aspects of Spinoza's vision of the universe, which drew sustained criticism from his contemporaries, is his claim that all events are determined by God to occur. Indeed, he maintains, even God does not freely choose to create the worldthis in sharp contrast to traditional views of God as creatorbut is determined by his own nature to produce what exists in the world. This determinism renders the structure of nature intelligible to the human intellect.

By understanding the necessary and eternal order of the world, humans may come to understand both their place in the world and what they ought to do in the world. By achieving this understanding, they may achieve a kind of nontheological immortality. Their reason, which grasps the unchanging and eternal order of nature, enables them to achieve a kind of immortality as well.

Nicolás Malebranche

Malebranche's philosophical system is a synthesis of Cartesian philosophy and Augustinian theology. In The Search after Truth, Malebranche seeks to remedy human ignorance by presenting the nature of the human mind and showing that it is only by heeding the perceptions of the pure intellect that human beings may achieve knowledge. In the course of elaborating this view, Malebranche develops his two most distinctive doctrines: the vision in God and occasionalism.

The vision in God is Malebranche's account of human knowledge of truths about the world. He claims that human beings may cognize general truths because they have access to those truths in God's mind; they must have access to truths in God's mind because general truths are eternal and infinite and therefore could not be contained in the finite human mind. Occasionalism is a general account of causation, according to which no finite being (whether a mind or a body) is the real cause of any change in the world. Malebranche maintains that a real causal connection must be one that is necessary; however, there is a necessary connection only between God's will and some effect. Consequently, apparent causes are merely occasions for the exercise of God's causal power in accordance with the natural laws constitutive of nature.

In the Treatise on Nature and on Grace, Malebranche deploys these doctrines in order to explain God's action in the created world. He seeks to show that the seeming imperfection of the natural world manifest in natural disasters and the birth of monsters, and the apparent inequality in God's distribution of grace, are merely apparent defects. Because God acts in accordance with general laws, and does not intervene directly to produce particular events, his action in the realms of nature and grace is essentially limited. Malebranche believes that God must act in accordance with general laws because if he were to intervene at every moment in the world, he would not act in accordance with his own nature. Moreover, the world would thereby cease to be intelligible to human beings. Occasionalism, consequently, guarantees the intelligible order of the universe.

Gottfried Wilhelm von Leibniz

Leibniz's philosophical system reflects an overarching commitment to the idea that there is a rational order to the universe that can be grasped by human minds. This commitment is manifest both in his more general epistemological and metaphysical views on display in works like the Monadology and in the philosophical theology contained in the Theodicy.

The foundation of Leibniz's philosophy is simple, soul-like substances, monads, which Leibniz believes are the only genuine substances in the universe. His argument rests on the claim that genuine substances must be simple, something he takes to be immediately evident to the human intellect. All other thingsbodies, human beings, and animalsmay be broken into their component parts; only minds are indivisible, and therefore only minds are substances.

Substantive metaphysical conclusions follow. Leibniz maintains that there may be no genuine causal interaction between substances, because genuine causal interaction would require that substances could be changed from without, thereby contravening their simplicity. Apparent changes are actually internal changes of substances. Because all changes are correlated with the states of all other monads, this "pre-established harmony" guarantees that apparent causal interactions will be grounded in actual changes in monads.

The idea of harmony lies at the heart of Leibniz's metaphysics. There is a preestablished harmony among the changes of substances; there is also a harmony between the order of nature and the order of grace, which ensures that the moral order will be realized. This point emerges clearly in Leibniz's claim that this is the best of all possible worlds. Here Leibniz seeks to defend God's goodness against the apparent visible evidence of all the evil in the world. According to Leibniz, this evil merely seems to tell against God's goodness. We know that God is a perfect being, and we know that a perfect being may act only in the best way. Consequently, the fact that God created this world reveals that it is the best of all possible worlds. The appearances that seem to tell against this are merely appearances, and we may therefore have confidence in the goodness and intelligibility of this world.

The Destiny of Rationalism

Kant's Critique of Pure Reason definitively limited the rationalists' pretensions to achieve knowledge of substantive truths by means of the intellect alone. Kant argues that knowledge is limited to the appearances presented to us by the senses; no extension of knowledge is possible to the "supersensible" or intelligible realm to which the rationalists, like Plato, purported to have access. Consequently, the rationalist belief in the capacity of the pure intellect to achieve knowledge of truths about the universe is revealed to be unfounded. Indeed, Kant's critique revealed that the rationalist commitment to pure intellect that can operate independently of the senses was untenable. Moreover, recent developments in science further reveal that the rationalist conception of the world as an intelligible order was overstated. Nevertheless, the rationalist commitment to the power of reason remained alive for Kant, particularly in his practical philosophy. Rationalism encouraged women to use their own reason in philosophy: Princess Elizabeth of Bohemia and Damaris Masham directly engaged Descartes and Leibniz, respectively, in correspondence; Margaret Cavendish and Anne Conway worked out a rationalist paradigm. Finally, from a historical standpoint most significantly, rationalism inspired Enlightenment thinkers to trust in human abilities without reliance on divine illumination.

See also Empiricism ; Epistemology ; Metaphysics .



Descartes, René. The Philosophical Writings of Descartes. 3 vols. Edited and translated by John Cottingham, Dugald Murdoch, Robert Stoothoff, and Anthony Kenny. Cambridge, U.K., and New York: Cambridge University Press, 19841991. Most complete English edition of Descartes's writings.

Kant, Immanuel. Critique of Pure Reason. Translated by Norman Kemp Smith. New York: St. Martin's, 1965. Classic, beautiful translation.

Leibniz, G. W. Philosophical Essays. Edited and translated by Roger Ariew and Daniel Garber. Indianapolis: Hackett, 1989. Good selection of Leibniz's writings, spanning his entire philosophical career.

. Theodicy: Essays on the Goodness of God, the Freedom of Man, and the Origin of Evil. Edited by Austin Farrer. Translated by E. M. Huggard. La Salle, Ill.: Open Court, 1985. The most readily available English translation.

Malebranche, Nicolás. The Search after Truth. Edited and translated by Thomas Lennon and Robert Olscamp. Cambridge, U.K., and New York: Cambridge University Press, 1997. The most recent English translation.

. Treatise on Nature and on Grace. Edited and translated by Patrick Riley. Oxford and New York: Oxford University Press, 1992. Fine edition; omits two of the Elucidations added by Malebranche.

Spinoza, Benedict de. The Collected Works of Spinoza, Vol. I. Edited and translated by Edwin Curley. Princeton, N.J.: Princeton University Press, 1985. Magisterial edition of Spinoza's early writings. Volume II is in preparation.

. Theological-Political Treatise. 2nd ed. Translated by Samuel Shirley. Indianapolis: Hackett, 2001. Best available English edition.


Garrett, Don. The Cambridge Companion to Spinoza. Cambridge, U.K.: Cambridge University Press, 1989. Essays cover most aspects of Spinoza's work.

Hatfield, Gary. "The Cognitive Faculties." In The Cambridge History of Seventeenth-Century Philosophy, edited by Daniel Garber and Michael Ayers. Cambridge, U.K.: Cambridge University Press, 1998. Seminal article; treats both rationalists and empiricists from the standpoint of the cognitive faculties.

. Routledge Philosophy Guidebook to Descartes and the Meditations. London: Routledge, 2002. Sustained interpretation of the Meditations as cognitive exercises; also considers alternative interpretations.

Nadler, Steven. The Cambridge Companion to Malebranche. Cambridge, U.K., and New York: Cambridge University Press, 2000. Essays cover most aspects of Malebranche's philosophical writings.

Rutherford, Donald. Leibniz and the Rational Order of Nature. Cambridge, U.K., and New York: Cambridge University Press, 1995. General interpretation of Leibniz's philosophy as motivated by the attempt to reveal the intelligible order of the universe.

Sean Greenberg

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Rationalism. Term employed to mean different things at different times by various groups in the history of C20 architecture, but mostly applied to mean the architectural principles behind the International Modern Movement led by such personalities as Gropius and Mies van der Rohe subscribing to the so-called Machine Aesthetic and to Functionalism. However, the word has been so loosely used that some expanded explanations are necessary.

Classical and Renaissance architectural treatises argued that architecture was a science with principles that could be understood on a rational basis. C18 and C19 theorists, notably J. -N. -L. Durand, Viollet-le-Duc, Semper, and others also argued for reasonable approaches to design derived from the culture of the European Enlightenment. Those arguing for C20 Rationalism did not have any one coherent theory, but made assumptions that architectural and urban problems could be solved primarily through an abandonment of Historicism and of movements such as the Arts-and-Crafts, Art Nouveau, and Expressionism (which they regarded as dead-ends), thus creating a tabula rasa on which to start again. They tended to be messianic in their desire for a new world, better architecture, Socialist structures, and a belief in the inherent rightness of what they were seeking, drawing on a Machine Aesthetic to achieve an appropriate image.

Advocates of Rationalism evolved certain principles by which their aims were to be met. First, architecture, industrial design, and planning could be used for social engineering and educational purposes, and so design had a moral meaning (a notion drawn partly from the writings of A. W. N. Pugin and Ruskin). Second, strict economy, cheap industrialized building methods, and a total absence of ornament were to be employed to achieve a minimum standard for everyone's habitation. Third, prefabrication, industrial technologies, and mass-production at all levels were to be used in the making of the new environment, but, even if traditional methods of construction were employed (bricks, after all, are mass-produced, standardized, prefabricated building-components), buildings should look machine-made in their pristine state (so brickwork was disguised by being covered with smooth render). Fourth, wholesale clearances, demolitions, and the destruction of existing urban fabric were deemed to be essential so that vast housing-estates could be erected. Lastly, form itself should be evolved for constructional, economic, functional, political, and social reasons, and so was not (in theory) subject to individual fancy (but in fact was largely determined by a few paradigms).

In practice, Rationalism encouraged an approved International style from which all historical and decorative elements were expunged, drawing on influences from e.g. Constructivism and de Stijl. Among key buildings were Gropius's Bauhaus, Dessau (1925–6), Le Corbusier's Maison Stein, Garches (1927), and houses at the Weissenhofsiedlung, Stuttgart (1927), while theoretical and unifying bases were provided by CIAM and certain writers, notably Giedion and Pevsner.

It is one of the curiosities of Rationalism that it flourished in Italy under Benito Mussolini's Fascist regime (1922–43), and in fact International Modernism was also called Rationalism by Gruppo 7. Terragni was perhaps the most distinguished Italian Rationalist, with his Fascist Party Headquarters, Como (1932–6). Gruppo 7 expanded to form the Movimento Italiano per l'Architettura Razionale (MIAR), inspired partly by Futurism. After the 1939–45 war Rationalism was adopted, virtually as the de rigueur style of Western Europe and America. Looked at objectively, it was just another style, drawing its motifs from a limited range of features approved in the 1920s, and owing very little to rationalism at all, but more to the desire for images thought to be appropriate for the times, and that, in any case, were usually only metaphors of mass-production, modernity, and industrialization.


Behne (1926);
Etlin (1991);
Giedion (1967, 1969);
Gropius (1952, 1962, 1965);
Hilbersheimer (1925, 1927a);
Koulermos (1995);
Lampugnani (ed.) (1988);
Mantero (1984);
Pevsner (1960, 1974a);
Placzek (ed.) and Robertson (1973);
T. Schumacher (1991);
Jane Turner (1996)
D. Watkin (1977)

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"Rationalism." A Dictionary of Architecture and Landscape Architecture. . 25 May. 2017 <>.

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rationalism [Lat.,=belonging to reason], in philosophy, a theory that holds that reason alone, unaided by experience, can arrive at basic truth regarding the world. Associated with rationalism is the doctrine of innate ideas and the method of logically deducing truths about the world from "self-evident" premises. Rationalism is opposed to empiricism on the question of the source of knowledge and the techniques for verification of knowledge. René Descartes, G. W. von Leibniz, and Baruch Spinoza all represent the rationalist position, and John Locke the empirical. Immanuel Kant in his critical philosophy attempted a synthesis of these two positions. More loosely, rationalism may signify confidence in the intelligible, orderly character of the world and in the mind's ability to discern such order. It is opposed by irrationalism, a view that either denies meaning and coherence in reality or discredits the ability of reason to discern such coherence. Irrational philosophies accordingly stress the will at the expense of reason, as exemplified in the existentialism of Jean-Paul Sartre or Karl Jaspers. In religion, rationalism is the view that recognizes as true only that content of faith that can be made to appeal to reason. In the Middle Ages the relationship of faith to reason was a fundamental concern of scholasticism. In the 18th cent. rationalism produced a religion of its own called deism (see deists).

See E. Heimann, Reason and Faith in Modern Society (1961); T. F. Torrance, God and Rationality (1971); R. L. Arrington, Rationalism, Realism, and Relativism (1989).

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"rationalism." The Columbia Encyclopedia, 6th ed.. . 25 May. 2017 <>.

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rationalism Used loosely to indicate a rejection of faith or religion, and more strictly a view that all knowledge can be expressed in the form of a system, and that, in principle, everything can be known. In sociology it is sometimes used to refer to the alternative offered by Max Weber to the empiricist natural science model. The strong version of rationalism, that knowledge (at least in the social sciences) comes from reason alone (as opposed to sense-experience), is sometimes supported by writers as different as Weber, Talcott Parsons, and Louis Althusser. More recently, rationalism has been regarded by those labelled as post-modernist as a failed product of the Enlightenment; but, as Jürgen Habermas points out, such an argument is itself a rational one, and therefore self-defeating. It is difficult to see how any attempt to know the social world can avoid at least some rationalist assumptions. See also EPISTEMOLOGY; IDEAL TYPE.

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"rationalism." A Dictionary of Sociology. . 25 May. 2017 <>.

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ra·tion·al·ism / ˈrashənlˌizəm; ˈrashnəˌlizəm/ • n. a belief or theory that opinions and actions should be based on reason and knowledge rather than on religious belief or emotional response: scientific rationalism. ∎ Philos. the theory that reason rather than experience is the foundation of certainty in knowledge. ∎ Theol. the practice of treating reason as the ultimate authority in religion. DERIVATIVES: ra·tion·al·ist n. ra·tion·al·is·tic / ˌrashənlˈistik; ˌrashnəˈlistik/ adj. ra·tion·al·is·ti·cal·ly / ˌrashənlˈistik(ə)lē; ˌrashnəˈlistik(ə)lē/ adv.

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"rationalism." The Oxford Pocket Dictionary of Current English. . 25 May. 2017 <>.

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rationalism Philosophical theory that knowledge about the nature of the world can be obtained solely by reason, without recourse to experience. Rationalist philosophers, such as Descartes, Leibniz, and Spinoza, argued that reality could be logically deduced from ‘self-evident’ a priori premises. It contrasts with empiricism. In theology, rationalism holds that faith be explicable by human reason rather than divine revelation.

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"rationalism." World Encyclopedia. . 25 May. 2017 <>.

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