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.

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.

I read Stefan Collini’s What are Universities For? last week with very mixed feelings. In the past, I’ve much admired his polemical essays on the REF, “impact”, the Browne Report, etc. in the London Review of Books and elsewhere: they speak to my heart. If you don’t know those essays, you can get some of their flavour from his latest article in the Guardian yesterday. But I found the book a disappointment. Perhaps the trouble is that Collini is too decent, (...) too high-minded, has too unrealistically exalted a view about what actually happens in universities which is too coloured by attitudes appropriate to the traditional humanities. And he is optimistic to the point of fantasy if he thinks that people are so susceptible to “the romance of ideas and the power of beauty” that they will want, or can be brought to want, lots and lots of universities in order to promote the ideas (as if they would suppose that the task of “conserving, understanding, extending and handing on to subsequent generations the intellectual, scientific, and artistic heritage of mankind” was clearly ill-served when there were only forty universities in England, as opposed to a hundred and whatever). (shrink)

What could be more certain than the fact that 2 plus 2 equals 4? Since the time of the ancient Greeks mathematicians have believed there is little---if anything---as unequivocal as a proved theorem. In fact, mathematical statements that can be proved true have often been regarded as a more solid foundation for a system of thought than any maxim about morals or even physical objects. The 17th-century German mathematician and philosopher Gottfried Wilhelm Leibniz even envisioned a ``calculus'' of reasoning such (...) that all disputes could one day be settled with the words ``Gentlemen, let us compute!'' By the beginning of this century symbolic logic had progressed to such an extent that the German mathematician David Hilbert declared that all mathematical questions are in principle decidable, and he confidently set out to codify once and for all the methods of mathematical reasoning. (shrink)

Worries about scientific objectivity seem never-ending. Social critics and philosophers of science have argued that invocations of objectivity are often little more than attempts to boost the status of a claim, while calls for value neutrality may be used to suppress otherwise valid dissenting positions. Objectivity is used sometimes to advance democratic agendas, at other times to block them; sometimes for increasing the growth of knowledge, at others to resist it. Sandra Harding is not ready to throw out objectivity (...) quite yet. For all of its problems, she contends that objectivity is too powerful a concept simply to abandon. In Objectivity and Diversity, Harding calls for a science that is both more epistemically adequate and socially just, a science that would ask: How are the lives of the most economically and politically vulnerable groups affected by a particular piece of research? Do they have a say in whether and how the research is done? Should empirically reliable systems of indigenous knowledge count as "real science"? Ultimately, Harding argues for a shift from the ideal of a neutral, disinterested science to one that prizes fairness and responsibility. (shrink)

Is methodological theory a priori or a posteriori knowledge? It is perhaps a posteriori improvable, somehow. For example, Duhem discovered that since scientists disagree on methods, they do not always know what they are doing. How is methodological innovation possible? If it is inapplicable in retrospect, then it is not universal and so seems defective; if it is, then there is a miracle here. Even so, the new explicit awareness of rules previously implicitly known is in itself beneficial. And so, (...) improved methodology may make for improved methods. Hence, methodology is in part descriptive, in part prescriptive. Knowing this, a methodologist might improve his own studies. For example, Popper would then not hasten to conclude from the fact that past scientists depended on positive evidence that they had better do so in future as well; perhaps a lesser concern with confirmation may increase the productivity of scientific inquiry. (shrink)

Critical realism claims to bring a significant improvement to social science, especially in comparison with empiricist and interpretive approaches. So far, however, it has fallen short of the high expectations it raises. Critical realist arguments are convincing on the philosophical or meta-theoretical level but the contributions of critical realism to social science in terms of research activities at the field level are less clear. Nonetheless, there is no way back. Moving forward requires that the practice of doing social scientific (...) research be no longer perceived as limited to the justification of specific knowledge claims but must be seen as an integral part of the cycle of scientific discovery. (shrink)

In his magnum opus, The Logic of Scientific Discovery (first published in German in 1934, English translation, 1959), Karl Popper make two fundamental philosophical moves. First, he relocates the center of gravity of the philosophical treatment of science around what he calls the problem of demarcation. This is the problem of distinguishing between science, on the one hand, and everything else on the other. (By contrast, his contemporaries of the Vienna Circle, whose positivism would prove the most influential (...) brand of empiricism of the day, located the center of gravity around the problem of linguistic meaning, and use a criterion according to which a statement is meaningful to the extent that one can identify verification conditions for it.) Popper excludes from science such things as logic, metaphysics, Freudian psychoanalysis, and Marx’s theory of history. Second, Popper propounds the doctrine of falsification, which handles the problem of demarcation, as well as answers David Hume’s shattering attack on science as the premier form of knowledge centuries before. The arguments he mounts for falsification would function also as an attack on any account of the scientific enterprise that, like positivism, adheres to the idea that science progresses logically from instances (given in observation or experience) to the high-order generalizations characteristic of mature scientific theory. In this small space I shall undertake neither to illuminate the nuances of Popper’s position, nor to trace the (numerous) lines of criticism that have accumulated against it some seventy years later. I shall busy myself instead with tracing a trajectory of thought on the subject of scientific reasoning and its relation to individual decision-making, reflecting on Popper’s contribution and on how his legacy might be further enlarged. (shrink)

While there has been considerable discussion regarding scientific discovery, we are still in the dark about what a "logic" of discovery should look like. In this work, the author argues that formal dialogue theory is the best candidate for a logic of discovery. Formal dialogue logic is explored in detail. More broadly, a view of knowledge is put forward which encourages exploring the epistemological aspects of discovery.

Science is about evaluation, persuasion and logic. In scientific debate, scientists collectively evaluate theories by persuading each other in regard to epistemological qualities such as deduction and fact. There is, however, a flaw intrinsic to evaluation-by-persuasion: an individual can attempt and even succeed in persuading others by asserting that their reasoning is logical when it is not. This is a problem since, from an epistemological perspective, it is not always transparent nor obvious when a persuasive assertion is actually (...) deductively warranted. Empirical research upon reasoning, indeed, supports the notion that assertions are often strongly persuasive for reasons other than their logic. The unreliability of the link between persuasion and logic raises an important methodological issue: how do scientists debate in a manner such that claimed but false “logical” arguments are ignored, and only warranted arguments get to determine theory preference? This need for soundness in debate is a particularly important epistemological concern in cases where the deductive qualities of persuasive argument are not overt, and so cannot be directly checked --such as when they are founded upon Bayesianism probabilistic coherence. The argument presented here is that scientists make the qualities of probabilistic and nonprobabilistic inference sound (and so warranted) through how they organize their debate. Scientists, I argue, abide by “epistemological quality control practices” that limit the persuasive power of unsound arguments upon theory evaluation. Examples of such debate quality control practices are publicness, clarity, openness to criticism, and the collective promotion of attempts at theory conjecture and refutation. Methodologically, these quality control practices are extralogical since they do not directly provide scientific inferences with additional logical warrantedness. They function instead in science to generate an epistemological evaluative environment in which persuasiveness is due, and only due, to logic (i.e. sound). Their methodological role is therefore to make what is warranted de papyri (in our principles of rationality – epistemologically competence) also what is persuasive in evaluation and debate de cognitio (in our exercise of such principles – epistemologically performance). Several limitations exist upon the soundness of Bayesian inferential coherence – surreptitious revision, logical omniscience, uncertain evidence, old evidence, and new hypotheses. Bayesianism, as a result, can only exist if it is pursued in a debate that is regulated by quality control practices over its inferences (for instance, practices that ensure there is autonomy of inference, diligence of inference, probity of evidence, auditability of inference and assiduousness of conjecture). In this context, one can reinterpret Popper’s concern with criticism, openness, refutation and conjecture, as deriving not (as he thought) directly from the needs of logic, but, indirectly, from the need of scientists to create epistemological soundness. (shrink)

Puzzle-solving, like several other everyday activities, appears in a more sophisticated and ramified form in the realm of natural science. Improving on Thomas Kuhn's rudimentary account of puzzles in science, this paper formulates logical and functional criteria for the occurrence of scientific puzzles, and examines the two-fold nature of their solutions. Then, with the aid of erotetic logic, puzzle-posing questions are identified, their presuppositional relations to scientific theory and explanations are explored, and a new tool for history (...) of science research is developed. (shrink)

In every domain, the philosopher finds some principle which is unfalsifiable in so far as all experience is interpreted in accordance with it. This principle is tautologous or analytic-within-its domain in that it defines fundamental terms with which it characterizes experiences: Newton’s Laws define “mass” and “the equality of times”; the Principle of the Rectilinear Propagation of LIght defines “light”; the Principle of Evolution defines “adaptation” and “natural selection”; and the Principle of the Conservation of Energy defines “a closed system.” (...) Moreover, each principle is employed as a methodological rule or a tacit imperative to the investigator to interpret experience or to draw inferences in accordance with it. Nevertheless, each principle has empirical content: not only by virtue of its place within its respective domain but also because there are sufficient rules of correspondence which make the statement-form empirically relevant; not only because the principle itself is taken to be true but also because empirical inferences are drawn in accordance with it. To construe these principles as mere counterfactuals would be clearly incorrect. Counterfactuals, as Rescher would characterize them, are “belief-contravening suppositions” because certain beliefs are excluded if one is to be consistent. Although this is certainly true of these principles, the range of beliefs contravened is far larger than those beliefs excluded in mere laws of nature. For, to give up these principles would be to give up explaining the entire domain of experience to which they are applicable. (shrink)

By the "logic of scientific knowledge," or simply "the logic of science" we mean the discipline in philosophy concerned with the application of the techniques and methods of logic to scientific knowledge. In studying certain aspects of the logic of scientific knowledge it is possible to employ successfully not only the methods of dialectical logic but those of formal logic. It is the latter that will be the special concern of the (...) present article. (shrink)

This essay argues that scientific discourse is amenable to interpretation and assessment from the perspective of the narrative paradigm and its attendant logic, narrative rationality. It also contends that this logic entails a revised conception of knowledge, one that permits the possibility of wisdom. The text analyzed is James D. Watson and Francis H. Crick's proposal of the double helix model of DNA.

In order to present the incidence of the dynamic turn in the logic of scientific research, we begin with a section, in this article, that deals with logical games as triggers of this dynamic turn in contemporary logic, together with the program of logical dynamics of information and interaction. We briefly introduce the main characteristics of the logic favorable to independence and the game-theoretical semantics, of dialogical logic, as well as the essential elements of this (...) program. Although from any of these points of view we have a list of logical tools to deal with more clearly epistemological issues, we highlight the role of dynamic epistemic logic, to which we dedicate the following section. There follows another one in which we enter the logical studies of abduction as one of the fundamental problems of contemporary epistemology and, in a new section, in terms of the theoretical constructs of the preceding sections, we present and explain a phenomenon that emerged in the field of linguistics, the case of the discovery of the Amazonian language pirahã, which should be considered an anomaly within the framework of the Chomskian theory. (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)

Introduction: Science and Common Sense Long before the beginnings of modern civilization, men ac- quired vast funds of information about their environment. ...

A fundamental question for philosophy of science asks, How is knowledge of the world created? A pragmatist approach is constructed to show how discovery and justification are tightly related during the creation of scientific knowledge. Procedural abduction, at the scientific level of Strict Abduction and higher, integrates the learnable and the logical quite thoroughly. Discovery and justification are functionally fused together within the organized process of procedural abduction by scientific communities. Four questions posed at the start are (...) answered by this pragmatist philosophy of science as follows. Is scientific creativity methodologically related to scientific justification? Answer: scientific creativity is integral to abductive procedures yielding scientific justification. Can a distinction between genuine science and pseudo-science be clearly defined? Answer: genuine science is distinguished by the application of procedural abduction at the level of Strict Abduction or higher. Does scientific knowledge achieve the legitimacy of scientific realism? Answer: procedural abduction legitimates the credibility of highly-confirmed hypotheses and hence justifies scientific realism. How are scientific communities responsible for establishing scientific knowledge? Answer: scientific communities using procedural abduction realize scientific knowledge. (shrink)

In this first English translation the author has included all of the original text and has added new footnotes, preface, and 150 more pages of text. The new material is conveniently starred. A monumental work which develops the view Popper calls "deductivism" --the theory of the deductive method of testing.--J. E. M.

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)

This two-volume work, first published in 1843, was John Stuart Mill's first major book. It reinvented the modern study of logic and laid the foundations for his later work in the areas of political economy, women's rights and representative government. In clear, systematic prose, Mill disentangles syllogistic logic from its origins in Aristotle and scholasticism and grounds it instead in processes of inductive reasoning. An important attempt at integrating empiricism within a more general theory of human knowledge, the (...) work constitutes essential reading for anyone seeking a full understanding of Mill's thought. Continuing the discussion of induction, Volume 2 concludes with Book VI, 'On the Logic of the Moral Sciences', in which Mill applies empirical reasoning to human behaviour. A crucial early formulation of his thinking regarding free will and necessity, this book establishes the centrality of 'the social science' to Mill's philosophy. (shrink)

We consider a logic which is semantically dual (in some precise sense of the term) to intuitionistic. This logic can be labeled as “falsification logic”: it embodies the Popperian methodology of scientific discovery. Whereas intuitionistic logic deals with constructive truth and non-constructive falsity, and Nelson's logic takes both truth and falsity as constructive notions, in the falsification logic truth is essentially non-constructive as opposed to falsity that is conceived constructively. We also briefly clarify (...) the relationships of our falsification logic to some other logical systems. (shrink)