In this article I will focus on the debate on the causality principle that originated in the light of quantum mechanics concerning Moritz Schlick and Karl Popper. The discovery of quantum mechanics led to a broad debate on the interpretation of the principle of causality. Schlick proposed that it should be understood as an empirically verifiable postulate, and therefore with limits regarding causal indeterminacy in quantum physics. This approach had an influence on some scientists, especially Werner Heisenberg. However, Popper would (...) develop a different way of understanding science because of the role played by unverifiable elements in theories that can nevertheless be falsified. It is precisely the discussion around the principle of causality that opens up different ways of understanding science. I will first try to analyse Schlick’s argument in the context of the debate that was taking place in the late 1920s in the light of the new quantum mechanics; secondly, I will look at the reception that Schlick’s idea of causality had in Heisenberg and the Copenhagen Interpretation; thirdly, I will analyse Popper’s argument against Schlick’s interpretation; finally, I will try to see the resonances of this debate in Heisenberg and other physicists. (shrink)

Karl Popper’s world 3 theory proposes that the products of the human mind can be considered a third world, partially autonomous of the mental and physical worlds, and real, because it can produce effects on both. When he first introduced the idea in 1960, he took even his close colleagues and students by surprise. Yet tracing the development of his idea shows a great deal in Popper’s previous work and thought led up to what seemed his startlingly new proposal. And (...) far from being the philosophy of his dotage, as some sneered, his world 3 proposal, once fully shaped, became a keystone of his thought. (shrink)

The inference from determinism to predictability, though intuitively plausible, needs to be qualified in an important respect. We need to distinguish between two different kinds of predictability. On the one hand, determinism implies external predictability , that is, the possibility for an external observer, not part of the universe, to predict, in principle, all future states of the universe. Yet, on the other hand, embedded predictability as the possibility for an embedded subsystem in the universe to make such predictions, does (...) not obtain in a deterministic universe. By revitalizing an older result—the paradox of predictability —we demonstrate that, even in a deterministic universe, there are fundamental, non-epistemic limitations on the ability of one subsystem embedded in the universe to predict the future behaviour of other subsystems embedded in the same universe. As an explanation, we put forward the hypothesis that these limitations arise because the predictions themselves are physical events which are part of the law-like causal chain of events in the deterministic universe. While the limitations on embedded predictability cannot in any direct way show evidence of free human agency, we conjecture that, even in a deterministic universe, human agents have a take-it-or-leave-it control over revealed predictions of their future behaviour. (shrink)

The recent republication of David Bloor's Knowledge and Social Imagery in a second edition provides an occasion to reappraise the celebrated work which launched the so-called Strong Programme in the sociology of scientific knowledge. This work embodies the general outlook and foundational principles in a way that is still characteristic of its descendents. Above all, the recent republication of Bloor's original book is evidence of the continuing interest and importance of the work, but it also provides the clearest evidence of (...) the shortcomings of the enterprise. The arguments presented in the bulk of the book have received relatively little attention by comparison with the principal tenets enunciated in the first few pages. Accordingly, a detailed examination is made of these original arguments which were so influential in establishing the sociology of scientific knowledge. A close analysis reveals their seemingly unnoticed vacuity, as well as a vast discrepancy between the radical tenets of the Strong Programme and the theses that are actually defended in the body of Bloor's text. In this sense, this article serves to complement and reinforce Mario Bunge's recent masterful survey of the field, which he describes as "a grotesque cartoon of scientific research.". (shrink)

Karl Popper and Paul Feyerabend were among the most influential philosophers of science of the twentieth century. Extensive studies have been dedicated to the development of their controversial relationship, which saw Feyerabend turning from a student and supporter of Popper to one of his harshest critics. Yet, it is not as well known that the rift between Popper and Feyerabend arose mainly in the context of their studies on the foundations of quantum mechanics, which has been the main subject of (...) their discussions for about two decades. This paper reconstructs in detail their diatribe over the foundations of quantum mechanics, emphasising also the major role that their personal relationship played in their distancing. (shrink)

In-principle restrictions on the amount of information that can be gathered about a system have been proposed as a foundational principle in several recent reconstructions of the formalism of quantum mechanics. However, it seems unclear precisely why one should be thus restricted. We investigate the notion of paradoxical self-reference as a possible origin of such epistemic horizons by means of a fixed-point theorem in Cartesian closed categories due to Lawvere that illuminates and unifies the different perspectives on self-reference.

The eminent mathematical physicist Sir Hermann Bondi once said: “There is no more to science than its method, and there is no more to its method than Popper has said.” Indeed, many regard Sir Karl Raimund Popper the greatest philosopher of science in our generation. Much of what Popper “has said” refers to physics, but physicists, generally speaking, have little knowledge of what he has said. True, Popper's philosophy of science and, in particular, his realistic interpretation of quantum mechanics deviates (...) considerably from the generally accepted doctrine. But as Popper, rightly I think, points out, it is precisely the proliferation of divergent theories which promotes the growth of scientific knowledge; it would be a danger for physics if physicists were dogmatically tied to a single theory or would not test their theory against alternatives. It is for this purpose that, on the occasion of the nonagenarian celebration of Popper's birthday, the present essay has been written. (shrink)

The corpus of physical theory is a paradigm of knowledge. The evolution of modern physical theory constitutes the clearest exemplar of the growth of knowledge. If the development of physical theory does not constitute an example of progress and growth in what we know about the Universe nothing does. So anyone interested in the theory of knowledge must be interested consequently in the evolution and content of physical theory. Crucial to the conception of physics as a paradigm of knowledge is (...) the way in which physical theory provides explanations of a vast diversity of natural phenomena on the basis of a very few fundamental principles. A central problem for the epistemologist is therefore what is theoretical explanation in physics? Here we can get good insight from what Redhead has said. Indeed one could agree with almost everything Redhead says and simply endorse much of his careful and extensive defence of the covering law account of explanation in the physical sciences at least as an ideal. However I shall, I fear, try the reader's patience by extending some of the considerations he introduced and raising those issues where we disagree, especially in the important area of statistical explanation. (shrink)

The object of this paper is to examine what evidence we can have for or against the truth of determinism, a doctrine often set forward by the proposition ‘every event has a cause’. I understand in this context by the cause of an event a set of prior conditions jointly sufficient for the occurrence of the event. Since the determinist is concerned with all physical states and not merely with changes of states, which are most naturally termed events, we may (...) phrase this claim more precisely as follows: There is for every physical state at some earlier instant a set of conditions jointly sufficient for its occurrence. (shrink)

A mechanism is presented by which a classical system could be described by the laws of quantum theory. Conflict with von Neumann's no-go theorem is avoided. Experimental predictions are made.

There has been an ongoing conflict regarding whether reality is fundamentally digital or analogue. Recently, Floridi has argued that this dichotomy is misapplied. For any attempt to analyse noumenal reality independently of any level of abstraction at which the analysis is conducted is mistaken. In the pars destruens of this paper, we argue that Floridi does not establish that it is only levels of abstraction that are analogue or digital, rather than noumenal reality. In the pars construens of this paper, (...) we reject a classification of noumenal reality as a deterministic discrete computational system. We show, based on considerations from classical physics, why a deterministic computational view of the universe faces problems (e.g., a reversible computational universe cannot be strictly deterministic). (shrink)

Karl Popper’s world 3 theory proposes that the products of the human mind can be considered a third world, partially autonomous of the mental and physical worlds, and real, because it can produce effects on both. When he first introduced the idea in 1960, he took even his close colleagues and students by surprise. Yet tracing the development of his idea shows a great deal in Popper’s previous work and thought led up to what seemed his startlingly new proposal. And (...) far from being the philosophy of his dotage, as some sneered, his world 3 proposal, once fully shaped, became a keystone of his thought. (shrink)

O tópico do trabalho é o fenômeno denominado por Popper “efeito Édipo”, e suas implicações para a epistemologia analítico-positivista, em particular para o Princípio de Unidade da Ciência. Com referência a Popper, a tese defendida é a de que ele não teve sucesso na tentativa de resolver as inconsistências geradas em sua obra pelo reconhecimento da possibilidade do “efeito Édipo” nas ciências humanas.