In September 2007, more than 100 philosophers came to Prague with the determination to approach Karl Popper's philosophy as a source of inspiration in many areas of our intellectual endeavor. This volume is a result of that effort.

Karl Popper (1902-1994) was one of the most influential philosophers of science of the 20th century. He made significant contributions to debates concerning general scientific methodology and theory choice, the demarcation of science from non-science, the nature of probability and quantum mechanics, and the methodology of the social sciences. His work is notable for its wide influence both within the philosophy of science, within science itself, and within a broader social context. Popper’s early work attempts to solve the problem of (...) demarcation and offer a clear criterion that distinguishes scientific theories from metaphysical or mythological claims. Popper’s falsificationist methodology holds that scientific theories are characterized by entailing predictions that future observations might reveal to be false. When theories are falsified by such observations, scientists can respond by revising the theory, or by rejecting the theory in favor of a rival or by maintaining the theory as is and changing an auxiliary hypothesis. In either case, however, this process must aim at the production of new, falsifiable predictions. While Popper recognizes that scientists can and do hold onto theories in the face of failed predictions when there are no predictively superior rivals to turn to. He holds that scientific practice is characterized by its continual effort to test theories against experience and make revisions based on the outcomes of these tests. By contrast, theories that are permanently immunized from falsification by the introduction of untestable ad hoc hypotheses can no longer be classified as scientific. Among other things, Popper argues that his falsificationist proposal allows for a solution of the problem of induction, since inductive reasoning plays no role in his account of theory choice. Along with his general proposals regarding falsification and scientific methodology, Popper is notable for his work on probability and quantum mechanics and on the methodology of the social sciences. Popper defends a propensity theory of probability, according to which probabilities are interpreted as objective, mind-independent properties of experimental setups. Popper then uses this theory to provide a realist interpretation of quantum mechanics, though its applicability goes beyond this specific case. With respect to the social sciences, Popper argued against the historicist attempt to formulate universal laws covering the whole of human history and instead argued in favor of methodological individualism and situational logic. Table of Contents 1. Background 2. Falsification and the Criterion of Demarcation a. Popper on Physics and Psychoanalysis b. Auxiliary and Ad Hoc Hypotheses c. Basic Sentences and the Role of Convention d. Induction, Corroboration, and Verisimilitude 3. Criticisms of Falsificationism 4. Realism, Quantum Mechanics, and Probability 5. Methodology in the Social Sciences 6. Popper’s Legacy 7. References and Further Reading a. Primary Sources b. Secondary Sources -/- . (shrink)

Reed argues that the architectures of knowledge representation in Object -Oriented Programming and in Ayn Rand's Objectivist epistemology are exactly isomorphic, and were first proposed at about the same time. These similarities did not result from mutual influence, but from the need to represent knowledge, in both systems, in accordance with the same facts of reality. Thanks to the isomorphism of knowledge representation in the two systems, logical techniques developed in the context of OOP, such as scope-tracking and inheritance, are (...) directly usable and useful in objective logic based on Objectivist epistemology. (shrink)

This article offers a discussion of Duhemian analysis of Newton's method in the Principia considering both the traditional response to this analysis and the more recent ones. It is argued that in General Scholium to the Principia, Newton is not advocating what Duhem suggests in his best-known criticism, but he is proposing something very close to the establishment of a logical priority of physics over metaphysics, a familiar thesis defended by the French physicist himself.

The aim of this essay is to emphasize a number of important points that will provide a better understanding of the history of philosophical thought concerning scientific knowledge. The main points made are: (a) that the principal way of viewing abstraction which has dominated the history of thought and epistemology up to the present is influenced by the original Aristotelian position; (b) that with the birth of modern science a new way of conceiving abstraction came into being which is better (...) characterized by the term idealization, the name that was later, in fact, to be used by scientists to describe their scientific activity; (c) that, however, on account of the influence of empirical and inductive philosophy, scientists have often not had sufficient methodological awareness of this new way of viewing abstraction; (d) that this new concept of abstraction has frequently been expressed in the framework of philosophies that lie outside the mainstream of contemporary epistemology or even exhibit marked anti-scientific tendencies; (e) that the theme of idealization has been taken up again in the last few decades and a great contribution in this direction has been made by the so-called Pozna school of methodology. (shrink)

This paper explores early Australasian philosophy in some detail. Two approaches have dominated Western philosophy in Australia: idealism and materialism. Idealism was prevalent between the 1880s and the 1930s, but dissipated thereafter. Idealism in Australia often reflected Kantian themes, but it also reflected the revival of interest in Hegel through the work of ‘absolute idealists’ such as T. H. Green, F. H. Bradley, and Henry Jones. A number of the early New Zealand philosophers were also educated in the idealist tradition (...) and were influential in their communities, but produced relatively little. In Australia, materialism gained prominence through the work of John Anderson, who arrived in Australia in 1927, and continues to be influential. John Anderson had been a student of Henry Jones, who might therefore be said to have influenced both main strands of Australian philosophical thought. (shrink)

Although there are quite a few directions in modern philosophy of mathematics that invoke some essential role for (quasi-)empirical material, this chapter will be devoted exclusively to what may be considered the seminal tradition. This enabled me to present the subject as one coherent whole and to forestall the discussion getting scattered in a diversity of directions without doing justice to any one of them. -/- Quasi-empiricism in this tradition is the view that the logic of mathematical inquiry is based, (...) like the logic of scientific discovery, on the bottom-up retransmission of falsity (by means of counterexamples) rather than the top-down transmission of axiomatic truth. Imre Lakatos, who originally introduced the distinction between Euclidean and quasi-empirical theories, construed mathematics as a quasi-empirical science following in essence Popper’s method of conjectures and refutations. His essay on Proofs and Refutations was an attempt to apply, and thereby to test, Popper’s critical method and fallibilist theory of knowledge in a field – mathematics – to which it had not primarily been intended to apply. While Popper’s proposal stood up gloriously to this test, the new application gave rise also to new insights, in particular the construal of proofs as thought experiments with a role similar to that of testing and corroborating experiments in science. -/- After examination of a number of examples of mathematical thought-experiments from this perspective, the doctrine of the relative autonomy of objective knowledge is focussed upon, a doctrine which is part and parcel of the dialectic of proofs and refutations and hence of the quasi-empiricist programme. -/- Some remarks on the educational implications of quasi-empiricism conclude this chapter. These implications have no direct bearing on the actual practice of teaching mathematics in the classroom, but are mainly, if not exclusively, concerned with the image of mathematics that is conveyed in education. (shrink)

The thesis investigates how the notion of ‘ontology’ has been used in the field of medical informatics and knowledge representation. Partly to investigate what an ‘ontology’ can be said to represent and what requirements we can have on a good ‘ontology’. The author studies the already existing medical terminologies and ‘ontologies’ to elucidate what theories they are based on. The terminological theories of Eugen Wüster and his legacy in medical informatics are studied. It is noted that terminological theories handling linguistic (...) entities are not suited for describing and representing medical theories, since these are assumed to refer to the real world, which consists of more than linguistics entities. In order to find a metaphysical theory in accordance with the world view that medical theories describe, the author turn to the critical realism of Karl Popper, Roy Bhaskar and Ilkka Niiniluoto. These theories, taken together with the metaphysical theories regarding universals of David M Armstrong and Ingvar Johansson, are used as a basis to find out what an ‘ontology’ can be said to represent, and what criteria and requirements we can have on a good ‘ontology’. Among the requirements presented in the thesis are stability, interoperability and the requirement that a good ‘ontology’ must be in accordance with our best available theories. Finally, it is discussed how these requirements and criteria can come into conflict with one another, and how one should reason when handling these trade-offs. The author emphasises the importance of including the medical expertise in the process of creating ‘ontologies’, in order to produce as useful and relevant ‘ontologies’ as possible. (shrink)

Some of Kepler's works seem very different in character. His youthful Mysterium cosmographicum (1596) argues for heliocentrism on the basis of metaphysical, astronomical, astrological, numerological and architectonic principles. By contrast, Astronomia nova (1609) is far more tightly argued on the basis of only a few dynamical principles. In the eyes of many, such a contrast embodies a transition from Renaissance to early modern science. I suggest that Karl Popper's fallibilist and piecemeal approach, and especially his theory of errors, might prove (...) extremely helpful in resolving such alleged tension. By abandoning the perspective of the inductivist philosophy of science, which is forced by its own standards to portray Kepler as a "sleepwalker", I focus on the method he followed: he never hesitated to discuss his own intellectual journey, offering a rational reconstruction of the series of false starts, blind alleys and failures he encountered. The critical dialogue he managed to establish in private correspondence with fellow astronomers he later transplanted into his printed works, whose structure closely resembles that of a dialogue, however implicit. (shrink)

I offer an explicit account of the underdetermination thesis as well as of the many challenges it poses to scientific realism; a way to answer to these challenges is explored and outlined, by shifting attention to the content of theories. I argue that, even if we have solid grounds (as I contend we do) to support that some varieties of the underdetermination thesis are true, scientific realism can still offer an adequate picture of the aims and achievements of science.

I explain how Karl Popper resolved the problem of induction but not the pragmatic problem of induction. I show that Popper’s solution to the pragmatic problem of induction is inconsistent with his solution to the problem of induction. I explain how Popper’s falsificationist epistemology can solve the pragmatic problem of induction in the same negative way that it solves the problem of induction.

This paper is a supplement to, and provides a proof of principle of, Kuhn vs. Popper on Criticism and Dogmatism in Science: A Resolution at the Group Level. It illustrates how calculations may be performed in order to determine how the balance between different functions in science—such as imaginative, critical, and dogmatic—should be struck, with respect to confirmation functions and rules of scientific method.

This text provides a detailed examination of realism as a philosophy of natural science and its implications for the practice of social science. It also summarises some of the central themes of realism and its relations with other philosophical traditions. Realism is seen as essentially an ontological doctrine which means that it shares with neo-pragmatism a critique of the predominantly epistemological stress – most evident in rationalism – of much recent philosophy. It is argued that on the relation between science (...) and philosophy, realism adopts intermediate position between the anti-philosophical philosophy of the pragmatists and the rationalist conception as the judge of science. In conclusion, new realist philosophy of science – newly defined against earlier versions of realism – is offered as a sufficient tool with which the endemic problems of the social sciences might be addressed. (shrink)

Natural resources are infinite. This is possible because humans can create theories whose potential goes beyond the limited imaginative capacity of the inventor. For instance, no number of people can work out all the economic potential of quantum theory. Economic Resources are created by an interaction of Karl Popper's Worlds 1, 2 and 3, the worlds of physics, psychology and the abstract products of the human mind, such as scientific theories. Knowledge such as scientific theories has unfathomable information content, is (...) universally applicable, and infinitely copyable. The point can be made with technological knowledge such as that embodied in the wheel. The theory of the wheel has un- bounded potential to be embodied in unforeseeable new technologies, is useful on the Moon as on Earth, and can be infinitely copied. Unlike a piece of land (using fixed factors), such knowledge shows increasing returns. This helps to explain Julian Simon's observation that "natural" resources are now less scarce than they used to be and why an increasing population can increase resources in the long-run. It was Simon's breakthrough to elaborate on the abstract character of "natural" resources. I further explore this abstract character and thereby explain why natural resources are infinitely expandable. Economic growth and the creation of natural resources depends on the rate of invention. F. Machlup's suggestion (Machlup 1962) that the opportunity for new inventions increases geometrically with the number of inventions at hand is acknowledged for its suggestiveness, but criticised for its conservative position. Frank Tipler's fascinating argument for indefinite economic growth (Tipler 1994), is reinforced by my argument by making a distinction between information in the engineer's sense and the infinite potential "information" in our scientific knowledge based on Popper's notion of information content. (shrink)

I argue that so-called 'background knowledge' in confirmation theory has little, if anything, to do with 'knowledge' in the sense of mainstream epistemology. I argue that it is better construed as 'background information', which need not be believed in, justified, or true.

I argue that the conception of reflective equilibrium that is generally accepted in contemporary philosophy is defective and should be replaced with a conception of fruitful reflective disequilibrium which prohibits ad hoc manoeuvres, encourages new approaches, and eschews all justification in favour of continuous improvement. I suggest how the conception of fruitful disequilibrium can be applied more effectively to moral enquiry, to encourage genuine progress in moral knowledge, if we make moral theory empirically testable by adopting a meta-ethical postulate which (...) is independently plausible. (shrink)

A very brief outline of Popper's methodology.