Described by the philosopher A.J. Ayer as a work of 'great originality and power', this book revolutionized contemporary thinking on science and knowledge. Ideas such as the now legendary doctrine of 'falsificationism' electrified the scientific community, influencing even working scientists, as well as post-war philosophy. This astonishing work ranks alongside The Open Society and Its Enemies as one of Popper's most enduring books and contains insights and arguments that demand to be read to this day.

This classic remains one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history.

The essays in this volume represent an approach to human knowledge that has had a profound influence on many recent thinkers. Popper breaks with a traditional commonsense theory of knowledge that can be traced back to Aristotle. A realist and fallibilist, he argues closely and in simple language that scientific knowledge, once stated in human language, is no longer part of ourselves but a separate entity that grows through critical selection.

The way in which knowledge progresses, and especially our scientific knowledge, is by unjustified anticipations, by guesses, by tentative solutions to our problems, by conjectures. These conjectures are controlled by criticism: that is, by attempted refutations, which include severely critical tests. They may survive these tests; but they can never be positively justified: they can neither be established as certainly true nor even as 'probable'. Criticism of our conjectures is of decisive importance: by bringing out our mistakes it makes us (...) understand the difficulties of the problems which we try to solve. This is how we become better acquainted with our problem, and able to propose more mature solutions: the very refutation of a theory - that is, of a tentative solution to our problem - is always a step forward that takes us nearer the truth. And this is how we can learn from our mistakes. As we learn from our mistakes our knowledge grows, even though we may never know - that is, know for certain. Since our knowledge can grow, there can be no reason here for despair of reason. And since we can never know for certain, the can be no authority here for any claim to authority, for conceit over our knowledge, or for smugness. The essays and lectures of which this book is composed apply this thesis to many topics, ranging from problems of the philosophy and history of the physical and social sciences to historical and political problems. (shrink)

Hailed on publication in 1957 as "probably the only book published this year that will outlive the century," this is a brilliant of the idea that there are ...

Popper formulates and explains his non-justificationist theory of knowledge. Science--empirical science--aims at true explanatory theories, yet it can never prove, finally establish, or justify any of its theories as true, not even if it is in fact a true theory. Science must continue to question and criticize all its theories, even those which happen to be true.

Karl Raimund Poppers (1902-1994) Hauptwerk, die Logik der Forschung (1934), gilt als Grundlagenwerk des kritischen Rationalismus. Der kritische Rationalismus zeigt, warum unser Wissen fehlbar ist und versteht den Erkenntnisfortschritt als Resultat von Hypothesenbildung und -widerlegung. Der Sammelband orientiert sich an der Gliederung der Logik der Forschung. Seine Beiträge kommentieren die jeweiligen Themen nach aktueller Forschungslage.

‘If in this book harsh words are spoken about some of the greatest among the intellectual leaders of mankind, my motive is not, I hope, to belittle them. It springs rather from my conviction that, if our civilization is to survive, we must break with the habit of deference to great men.’ - Karl Popper, from the Preface Written in political exile during the Second World War and first published in two volumes in 1945, Karl Popper’s _The Open Society and (...) Its Enemies _is one of the most influential books of all time. Hailed by Bertrand Russell as a ‘vigorous and profound defence of democracy’, its now legendary attack on the philosophies of Plato, Hegel and Marx exposed the dangers inherent in centrally planned political systems and through underground editions become an inspiration to lovers of freedom living under communism in Eastern Europe. Popper’s highly accessible style, his erudite and lucid explanations of the thoughts of great philosophers and the recent resurgence of totalitarian regimes around the world are just three of the reasons for the enduring popularity of _The Open Society and Its Enemies_ and why it demands to be read today and in years to come. (shrink)

First published in 1986. Routledge is an imprint of Taylor & Francis, an informa company.

The basic theme of Popper's philosophy--that something can come from nothing--is related to the present situation in physical theory. Popper carries his investigation right to the center of current debate in quantum physics. He proposes an interpretation of physics--and indeed an entire cosmology--which is realist, conjectural, deductivist and objectivist, anti-positivist, and anti-instrumentalist. He stresses understanding, reminding us that our ignorance grows faster than our conjectural knowledge.

At the age of eight, Karl Popper was puzzling over the idea of infinity and by fifteen was beginning to take a keen interest in his father's well-stocked library of books. Unended Quest recounts these moments and many others in the life of one of the most influential thinkers of the twentieth century, providing an indispensable account of the ideas that influenced him most. As an introduction to Popper's philosophy, Unended Quest also shines. Popper lucidly explains the central ideas in (...) his work, making this book ideal for anyone coming to Popper's life and work for the first time. (shrink)

The Open Universe is the centerpiece of the argument of the Postscript.

"Bartley and Radnitzky have done the philosophy of knowledge a tremendous service. Scholars now have a superb and up-to-date presentation of the fundamental ideas of evolutionary epistemology." --Philosophical Books.

One of the most influential thinkers of the 20th century, Sir Karl Popper here examines the problems connected with human freedom, creativity, rationality and the relationship between human beings and their actions. In this illuminating series of papers, Popper suggests a theory of mind-body interaction that relates to evolutionary emergence, human language and what he calls "the three worlds." Rene; Descartes first posited the existence of two worlds--the world of physical bodies and the world of mental states. Popper argues for (...) the existence of "world 3" which comprises the products of our human minds. He examines the interaction between mental states--hopes, needs, plans, ideologies or hypotheses--and the physical states of our brain. Popper forcefully argues against the materialism forwarded by many philosophers which denies the existence of mental states. Instead, he demonstrates that the problem of the interaction between mental and physical states remains unresolved. Knowledge and the Body-Mind Problem is based on Popper's never-before published lectures at Emory University in 1969. Popper has extensively revised the lectures but has retained their accessible format. He has also incorporated some of the discussions which followed the lectures, providing an engaging exchange between the philosopher and his audience. (shrink)

_'Never before has there been so many and such dreadful weapons in so many irresponsible hands.'__ - Karl Popper, from the Preface_ _All Life is Problem Solving_ is a stimulating and provocative selection of Popper's writings on his main preoccupations during the last twenty-five years of his life. This collection illuminates Popper's process of working out key formulations in his theory of science, and indicates his view of the state of the world at the end of the Cold War and (...) after the collapse of communism. (shrink)

Quantum Theory and the Schism in Physics is one of the three volumes of Karl Popper’s Postscript to the Logic of scientific Discovery . The Postscript is the culmination of Popper’s work in the philosophy of physics and a new famous attack on subjectivist approaches to philosophy of science. Quantum Theory and the Schism in Physics is the third volume of the Postscript . It may be read independently, but it also forms part of Popper’s interconnected argument in the Postscript (...) . It presents Popper’s classic statement on quantum physics and offers important insights into his thinking on problems of method within science and physics as a whole. (shrink)

'I want to begin by declaring that I regard scientific knowledge as the most important kind of knowledge we have', writes Sir Karl Popper in the opening essay of this book, which collects his meditations on the real improvements science has wrought in society, in politics and in the arts in the course of the twentieth century. His subjects range from the beginnings of scientific speculation in classical Greece to the destructive effects of twentieth century totalitarianism, from major figures of (...) the Enlightenment such as Kant and Voltaire to the role of science and self-criticism in the arts. The essays offer striking new insights into the mind of one of the greatest twentieth century philosophers. (shrink)

Realism and the Aim of Science is one of the three volumes of Karl Popper’s Postscript to the Logic of scientific Discovery. The Postscript is the culmination of Popper’s work in the philosophy of physics and a new famous attack on subjectivist approaches to philosophy of science. Realism and the Aim of Science is the first volume of the Postcript . Popper here formulates and explains his non-justificationist theory of knowledge: science aims at true explanatory theories, yet it can never (...) prove, or justify, any theory to be true, not even if is a true theory. Science must continue to question and criticise all its theories, even those that happen to be true. Realism and the Aim of Science presents Popper’s mature statement on scientific knowledge and offers important insights into his thinking on problems of method within science. (shrink)

The World of Parmenides is a unique collection of essays that not only explores the complexity of ancient Greek thought, but also reveals Popper's engagement with Presocratic philosophy and the enlightenment he experienced in reading Parmenides. It includes writings on Greek science, philosophy and history and demonstrates Popper's life-long fascination with the presocratic philosophers, in particular Parmenides, Xenophanes and Heraclitus.

A sampling of the philosophical writings of Karl Popper includes discussions of rationalism, knowledge, human freedom, and the scientific method.

In this long-awaited volume, Jeremy Shearmur and Piers Norris Turner bring to light Popper's most important unpublished and uncollected writings from the time of The Open Society until his death in 1994. After The Open Society: Selected Social and Political Writings reveals the development of Popper's political and philosophical thought during and after the Second World War, from his early socialism through to the radical humanitarianism of The Open Society. The papers in this collection, many of which are available here (...) for the first time, demonstrate the clarity and pertinence of Popper's thinking on such topics as religion, history, Plato and Aristotle, while revealing a lifetime of unwavering political commitment. After The Open Society illuminates the thought of one of the twentieth century's greatest philosophers and is essential reading for anyone interested in the recent course of philosophy, politics, history and society. (shrink)

Karl R. Popper; I.—Back to the Pre-Socratics: The Presidential Address, Proceedings of the Aristotelian Society, Volume 59, Issue 1, 1 June 1959, Pages 1–24, ht.

Bertrand Russell described this study, with its companion volume on Hegel and Marx, as 'a work of first-class importance which ought to be widely read for its masterly criticism of the enemies of democracy, ancient and modern. His (Popper's) attack on Plato, while unorthodox, is in my opinion thoroughly justified. His analysis of Hegel is deadly. Marx is dissected with equal acumen, and given his due share of responsibility for modern misfortunes. The book is a vigorous and profound defence of (...) democracy, timely, very interesting, and very well written'. 'A powerful and important book. It is a criticism of a set of dogmas which underlie the most influential political theories, and in consequence powerfully affect the actual conduct of human affairs. Dr Popper writes with extreme clarity and vigour. His studies in Greek history and Greek thought have obviously been profound and original. Platonic exegesis will never be the same again. Nor, I think, will Marxist exegesis. Readers should not miss studying the notes collected at the end of the two volumes.' - Gilbert Ryle, Mind. (shrink)

First published in 1988. Routledge is an imprint of Taylor & Francis, an informa company.

A brief historical comment on scientific knowledge as Socratic ignorance -- Some critical comments on the text of this book, particularly on the theory of truth Exposition [1933] -- Problem of Induction (Experience and Hypothesis) -- Two Fundamental Problems of the Theory of Knowledge -- Formulation of the Problem -- The problem of induction and the problem of demarcation -- Deductivtsm and Inductivism -- Comments on how the solutions are reached and preliminary presentation of the solutions -- Rationalism and empiricism-deductivism (...) and inductivism -- The possibility of a deductivist psychology of knowledge -- The Problem of Induction -- The infinite regression (Hume's argument) --The inductivist positions -- The Normal-Statement Positions -- The normal-statement positions: naive inductivism, strict positivism and apriorism -- Critique of strict positivism - twofold transcendence of natural laws -- The transcendental method - presentation of apriorism -- Critique of apriorism -- Kant and Fries -- Supplement to the critique of apriorism. (Psychologism and transcendentalism in Kant and Fries.-On the question of the empirical basis.) -- Probability Positions -- The probability positions - subjective belief in probability -- Statements about the objective probability of events -- Probability as an objective degree of validity of universal empirical statements -- One way of more closely defining the concept of the probability of a hypothesis (primary and secondary probability of hypotheses). The concept of simplicity -- The concept of the corroboration of a hypothesis - positivist, pragmatist and probabilistic interpretations of the concept of corroboration -- The infinite regression of probability statements -- Pseudo-Statement Positions -- The pseudo-statement positions: new formulation of the problem -- Natural laws as "instructions for the formation of statements" -- "True - false" or "useful - useless"? Consistent pragmatism --Difficulties of consistent pragmatism -- Tool and schema as purely pragmatic constructs -- Natural laws as propositional functions -- Conventionalism -- The pseudo-statement positions will temporarily be put away: conventionalism -- The three interpretations of axiomatic systems. (The circle of problems surrounding conventionalism) -- Conventionalist implicit and explicit definitions Propositional function and propositional equation -- Conventionalist propositional equations as tautological general implications -- Can axiomatic-deductive systems also be understood as consequence classes of pure propositional functions (of pseudo-statements)? -- The coordinative definitions of empiricism: synthetic general implications -- Conventionalist and empiricist interpretations, illustrated by the example of applied geometry -- Strictly Universal Statements and Singular Statements -- Implication and general implication -- General implication and the distinction between strictly universal and singular statements -- Universal concept and individual concept-class and element -- Strictly universal statements-the problem of induction and the problem of universals -- Comments on the problem of universals -- Back to the Pseudo-Statement Positions -- Return to the discussion of the pseudo-statement positions -- Symmetry or asymmetry in the evaluation of natural laws? -- The negative evaluation of universal statements. Critique of the strictly symmetrical interpretation of pseudo-statements -- An infinite regression of pseudo-statements -- An apriorist pseudo-statement position -- Interpretation of the critique up to this point; comments on the unity of theory and practice -- A last chance for the pseudo-statement positions -- Pseudo-Statement Positions and the Concept of Meaning -- The concept of meaning and logical positivism -- The concept of meaning and the demarcation problem-the fundamental thesis of inductivism -- Critique of the inductivist dogma of meaning -- Fully decidable and partially decidable empirical statements-the antinomy of the knowability of the world. (Conclusion of the critique of the pseudo-statement positions.) -- The dialectical and the transcendental corroboration of the solution -- Is the problem of induction solved? (shrink)

We express here the statement » The probability of a given b equals r « symbolically by » p = r «. A formal axiomatic calculus can be constructed comprising all the well‐known laws of probability theory. This calculus can be interpreted in various ways. The present paper is a criticism of the subjective interpretation; that is to say, of any interpretation which assumes that probability expresses degrees of incomplete knowledge: a is the statement incompletely known, b is our total (...) knowledge, and p is the degree to which a is entailed by b. The subjective interpretation has often been proposed as an explanation and even a sharpening of the various objective theories . It is shown in the paper that this proposal cannot be realised because the subjective theory cannot lead to results which are compatible with the objective theory. This is due to various reasons, the most important of which is that the objective theory interprets » b « in » p « as a statement of the objective conditions of an experiment and » a « as one of its possible results. The subjective theory on the other hand interprets » b « as our total relevant knowledge which will in general include some knowledge of previous results of the experiment. It is shown that this must lead to incompatibility owing to the fact that this knowledge of previous results must influence the value of the probability.It is shown, in this way, that any probabilistic theory of the process of learning from experience—that is to say, any probabilistic theory of induction—must lead to contradictions.RésuméL'énoncé: » La probabilité de a, si b est donné, est égale à r « est ici exprimé symboliquement par » p = r «. On peut construire un système axiomatique formel qui contient toutes les règles bien connues du calcul des probabilités. Ce calcul formel peut ětre interprété de manières très différentes. L'article contient une critique des interprétations subjectives, c'est‐à‐dire des interprétations qui admettent que la probabilité exprime des degrés de connaissance incomplète: a est un énoncé qu'on ne connaǐt que partiellement, b est notre connaissance totale, et p exprime le degré auquel a est implicitement contenu dans b. L'interprétation subjective a souvent été proposée comme une explication et un renforcement des différentes théories objectives . Dans cet article, l'auteur montre que ce projet n'est pas réalisable, car la théorie subjective mène à des résultats qui contredisent la théorie objective. Plusieurs circonstances sont responsables de cette situation; la plus importante, c'est que la théorie interprète le » b « dans » p « comme une description des conditions objectives d'une expérience . D'autre part, la théorie subjective interprète » b « comme notre savoir total , et ce savoir inclura en général des informations sur les résultats obtenus antérieurement pour cette expérience. L'auteur montre que ce fait conduit à une contradiction entre les deux interprétations, car cette connaissance doit avoir une influence sur la valeur subjective de la probabilité.A l'aide de ce raisonnement, on peut montrer que la théorie des probabilités appliquée au processus inductif tirant une expérience du domaine expérimental conduit à des contradictions.ZusammenfassungDie Aussage » Die Wahrscheinlichkeit von a, wenn b gegeben ist, ist gleich r « wird hier symbolisch durch » p = r « ausgedrückt. Ein formales Axiomensystem kann konstruiert werden, das alle die wohlbekannten Regeln der Wahrscheinlichkeitsrechnung enthält. Dieser formale Kalkül kann in sehr verschiedener Weise interpretiert werden. Der Artikel enthält eine Kritik der subjektiven Interpretationen; das heisst, jener Interpretationen die annehmen, dass die Wahrscheinlichkeit Grade von unvollständigem Wissen ausdrückt: a ist ein Satz der unvollständig gewusst wird, b ist unser Gesamtwissen, und p drückt den Grad aus zu dem a in b implizit enthalten ist. Die subjektive Interpretation wurde oft als eine Erklärung und Verschärfung der verschiedenen objektiven Theorien vorgeschlagen. In dem Artikel wird gezeigt, dass der Vorschlag undurchführbar ist, da die subjektive Theorie zu Resultaten führt, die der objektiven Theorie widersprechen. Verschiedene Umstände tragen zu dieser Situation bei. Der wichtigste dieser Umstände ist, dass die objektive Theorie das » b « in » p « als eine Beschreibung der objektiven Bedingungen eines Experimentes interpretiert . Andererseits interpretiert die subjektive Theorie » b « als unser Gesamtwissen , und dieses wird im allgemeinen Informationen bezüglich früherer Resultate dieses Experiments einschliessen. Es wird gezeigt, dass das zu einem Widerspruch zwischen den Interpretationen führt, da dieses Wissen Einfluss auf den subjektiven Wahrscheinlichkeitswert haben muss.Mit Hilfe dieses Gedankenganges wird gezeigt, dass die Wahrscheinlichkeitstheorie des induktiven Lernens aus der Erfahrung zu Widersprüchen führt. (shrink)