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; Rene 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 Newton’s success was due to his adherence to Bacon’s 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).
ENLIGHTENMENT RADICALISM AND THE ROMANTIC REACTION
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 Quetelet, 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 Smith’s 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).
MARX AND AFTER
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.
Marx’s 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 Marx’s 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).
VARIANTS OF RATIONALISM
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 Grunbaum). The only consensus is about the defiance of reason (S0ren 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 welcome—as 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
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 a 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 cultural—or even aesthetic. The only intellectual justification of a scientific theory, said Einstein, is its ability to explain; its best reward is its successor’s 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 rationalism—as well as between them and fideism.
The agenda of rationalism—in philosophy, in science, or in practice—is 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.
