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Popper, Karl

Popper, Karl 1902-1994


Sir Karl Raimund Popper was a leading twentieth-century philosopher. His first major work, Logik der Forschung (The Logic of Scientific Discovery, 1935), was a methodology of the physical sciences that dispensed with induction. His second major work, in two volumes, The Open Society and Its Enemies (1945), was a democratic manifesto that burst out of broad yet incisive discussions of the philosophy of history, society, and politics. Slightly less influential was his slim, sober Poverty of Historicism (1957).

David Humes (17111776) critique of induction that universal statements of science never follow deductively from particular statements describing experience inadvertently undermined the rationality of science. His own response to his critique was to base inductive inferences on habit rather than on rationality. Immanuel Kants (17241804) response was to base inductive inferences on the principle of induction (or of simplicity, as he called it), whose status is that of extralogical truth known with no recourse to experience: synthetic a priori knowledge. Most philosophers find Humes response a retreat to irrationalism and Kants response a retreat to dogmatism. They sought a different way around Humes critique. Thus, the problem of induction, the search for a satisfactory response to Humes critique, became a central concern of rationalist philosophy. Popper reworded the problem: how is theoretical learning from experience possible? To this, he had a new solution: learning from experience is deductive; it advances by the refutation of bold conjectures; and the bolder the better. The view of learning from experience by refutations is impervious to Humes critique: a statement of experience conflicts with a theory. Thus, contrary to Kant, Popper viewed science as no knowledge, much less as a priori knowledge. Science then is the search for explanatory conjectures and for ways to test them. He thus shifted traditional epistemology from the positive to the negative, to via negativa : groping in the dark and learning from error. He likewise turned traditional positive epistemology into Socratic negative epistemology: we know that we do not know, we know the limitations of some theories. Our pursuit of knowledge engenders our best and most interesting errors.

Poppers view aimed to account for the progress of science, not for its alleged reliability. On this he made three very important comments. First, absolute reliability is impossible and conditional reliability is question-begging. Second, most applied theories and the most frequently applied onesGalileos (15641642) and Isaac Newtons (16421727)are refuted. Third, current efforts to answer Hume must be hopeless and useless. In particular, reliability is not probability; to the extent that it is possible it is the elimination of some dangerous applications of science achieved by severe tests. Following probability is caution, whereas scientific thinking is bold and so are attempts to apply it. Yet because theories are hypotheses that invite critical discussion, a testable theory of induction may be welcome, but most proposed solutions of the problem of induction are untenstable and so they are pseudoscientific.

Poppers contribution to social and political philosophy accords with his negative philosophy of science. It is more significant, both politically and intellectually. He argued that any regime that safeguards the means for peaceful corrections of government errors deserves respect as a democracy. Politics invites criticism aimed at improvements, he observed, and seeking improvements is superior tomore fruitful thanthe traditional theory of the sovereign that is a futile search for the best regime. This is the central message of Poppers philosophy, both theoretical and practical, regarding science, government, and anything else worthwhile: improving is preferable to legitimating. He took particular aim at intellectuals, arguing that they had moral responsibilities commensurate with their privileges and that they had a long history of falling short. As examples, he expounded the ideas of two of his greatest intellectual heroes, Plato (427347 BCE) and Karl Marx (18181883). He claimed that their devotees glossed over the defects of their philosophies, especially their illiberalism. His doctrine that great men make great mistakes from which we should learn was more challenging than his negative epistemology.

Popper deemed unscientific the doctrines of historical inevitability or historical destiny (historicism in his jargon) of Plato and of Marx. He said that no doctrine of this kind can be worded in a manner clear enough to be put to the test of experience, because if such a theory were to cohere with known facts, it must be vague. (Irrefutable versions of historicism are easy to invent: the simplest is the purely existential historical destiny exists.) Ingeniously, Popper found a way to refute all reasonable versions of historicism, despite its inherent vagueness. The argument deploys two intuitive premises: future science is in principle unpredictable, and its impact on society is tremendous. Hence, no large-scale theory of the future development of society can possibly yield significant or interesting predictions.

Poppers mode of thinking leads to his greatest and most significant idea. It is his replacement of the theory of rationality that characterizes Western philosophy. Most people take for granted the idea that the best culture is their own. The first to reject this idea as too complacent were the leading ancient Greek philosophers. They deemed problematic all cultures, and what cultures espouse as true they declared to be nonbinding, conventional truths. They deemed binding only universal, absolute truthstruths by nature. Proof is required to show that an assertion is true by nature.

Popper challenged this doctrine: applying the Socratic maxims to science, he declared its rationality to rest neither on proof nor on surrogate proof but on willingness to engage in critical debate. This willingness creates a balance between tradition and science, between conservative and radical politics, between the given and the hoped for: it is a plea for reformist democracy, a view of scientific progress as an approximation to the truth and to freedom and justice, a view that applies to all walks of life, a remarkable and exciting move towards a synthesis and a challenge to push it forward. As the root of rationality is willingness to debate, reform is secondary to the replacement of both traditionalism and radicalism with the advocacy of individual autonomy.

SEE ALSO Philosophy of Science


Agassi, Joseph. 1988. Sir Karl Popper in Retrospect: The Positive Power of Negative Thinking. In The Gentle Art of Philosophical Polemics, ed. Joseph Agassi, 479501. LaSalle IL: Open Court.

Bunge, Mario, ed. 1964. The Critical Approach to Science and Philosophy. London and New York: Free Press.

Kekes, John. 1977. Popper in Perspective. Metaphilosophy 8:3661.

Levinson, Paul, ed. 1982. In Pursuit of Truth: Essays in Honour of Karl Popper on the Occasion of his 80th Birthday. Atlantic Highlands, NJ: Humanities Press.

Magee, Bryan. 1985. Philosophy and the Real World: An Introduction to Karl Popper. Chicago: Open Court.

Magee, Bryan. 1985. Popper. 3rd ed. London: Fontana.

Miller, David, ed. 1985. Popper Selections. Princeton, NJ: Princeton University Press.

OHear, Anthony, ed. 1995. Karl Popper: Philosophy and Problems. Cambridge, U.K.: Cambridge University Press.

Popper, Karl. 1945. The Open Society and Its Enemies. 2 vols. London: Routledge and Kegan Paul.

Popper, Karl. 1957. The Poverty of Historicism. London: Routledge and Kegan Paul.

Popper, Karl. [1935] 1959. The Logic of Scientific Discovery. London: Hutchinson. (Originally published as Lokig der Forschung.)

Popper, Karl. 1963. Conjectures and Refutations: The Growth of Scientific Knowledge. London: Routledge and Kegan Paul.

Schilpp, Paul Arthur, ed. 1974. The Philosophy of Karl Popper. 2 vols. La Salle, IL: Open Court.

Joseph Agassi

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Sir Karl Raimund Popper

Sir Karl Raimund Popper

The Austrian philosopher Sir Karl Raimund Popper (1902-1994) offered an original analysis of scientific research that he also applied to research in history and philosophy.

Karl Popper was born in Vienna on July 28, 1902, the son of a barrister. He studied mathematics, physics, and philosophy at the University of Vienna. Though not a member of the Vienna Circle, he was in sympathy with some, if not all, of its aims. His first book, The Logic of Scientific Discovery (1935), was published in a series sponsored by the Circle. In 1937 Popper accepted a post in New Zealand as senior lecturer in philosophy at Canterbury University College in Christchurch.

At the end of World War II, Popper was invited to the London School of Economics as a reader, and in 1949 he was made professor of logic and scientific method. Popper then made numerous visits to the United States as visiting professor and guest lecturer. In 1950 he gave the William James Lectures at Harvard University. In 1965 Popper was knighted by Queen Elizabeth II.

Foundations of Popper's Theory

Popper's first book laid the foundations for all the rest of his work. It offered an analysis of the procedure to be used in scientific work and a criterion for the meaning of the statements produced in such work. According to Popper, the researcher should begin by proposing hypotheses. The collection of data is guided by a theoretical preconception concerning what is relevant or important. The examination of causal connections between phenomena is also guided by leading hypotheses. Such a hypothesis is scientific only if one can derive from it particular observation statements that, if falsified by the facts, would refute the hypothesis. A statement is meaningful, therefore, if and only if there is a way it can be falsified. Hence the researcher should strive to refute rather than to confirm his hypotheses. Refutation is real advancement because it clears the field of a likely hypothesis.

Understanding History and Society

Popper later applied his analysis of knowledge to theories of society and history. In The Open Society and Its Enemies (1945) he attacked Plato, G. W. F. Hegel, and Karl Marx as offering untenable totalitarian theories that are easily falsifiable. The Open Society is often considered one of Popper's most influential books of this century. It also was responsible for the prevalent use of the term "open society." Critics argue that Popper succeeded in this book and in its sequel, The Poverty of Historicism (1957), in formulating a deterministic theory about general laws of historical development and then refuting it. A lively controversy ensued on the issue of which philosophers, if any, held the doctrine Popper refuted. Popper found himself embroiled in a decade of polemics, particularly with partisans of Plato. Popper was thus credited with a convincing logical refutation but one misdirected in its targets.

Popper's later works Objective Knowledge (1972) and The Self and Its Brain (1977) combined his scientific theory with a theory of evolution. In the 1980s, Popper continued to lecture, focusing mainly on questions of evolution and the role of consciousness. Karl Popper died of complications from cancer, pneumonia, and kidney failure on September 17, 1994 at the age of 92.

Further Reading

A work in progress edited by Paul A. Schilpp, The Philosophy of Karl Popper, will contain a biographical sketch, critical essays, and Popper's replies and should become the definitive work. In the interim the best study is Mario Bunge, ed., The Critical Approach to Science and Philosophy (1964), a Festschrift for Popper's sixtieth birthday containing essays by distinguished scholars and a bibliography complete to 1964.

Additional Sources

O'Mear, Anthony, Karl Popper, Cambridge University Press, 1995.

Popper, Karl Raimund, Unended Quest: An Intellectual Autobiography, Open Court, 1978.

Honderich, Ted, ed., Oxford Companion to Philosophy, Oxford University Press, 1995.

The New York Times, September 18, 1994. □

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