In this paper we prove some results about the complexity of proofs. We consider proofs in Hilbert-style formal systems such as in [17]. Thus a proof is a sequence offormulas satisfying certain conditions. We can view the formulas as being strings of symbols; hence the whole proof is a string too. We consider the following measures of complexity of proofs: length , depth and number of steps For a particular formal system and a given formula A we consider the shortest (...) length of a proof of A , the minimal depth of a proof of A and the minimal number of steps in a proof of A . The main results are the following: a bound on the depth in terms of the number of steps: Theorem 2.2, a bound on the depth in terms of the length: Theorem 2.3, a bound on the length in terms of the number of steps for restricted systems: Theorem 3.1. These results are applied to obtain several corollaries. In particular we show: a bound on the number of steps in a cut-free proof, some speed-up results, bounds on the number of steps in proofs of Paris-Harrington sentences. Some papers related to our research are listed in the references. We were especially influenced by Parikh's paper [17] on the famous conjecture of Kreisel . Many important problems in this field remain open. We hope that our paper will contribute to progress in this area. It should be noted that some results of this paper can be equally well obtained using unification theory , by translating a complexity-of-proof problem into a unification problem. A unification algorithm solving the unification problem can then be constructed and the complexity of the unification algorithm analyzed. As pointed out by the referee this method can be used to solve the problem stated in Section 3 for some non-simple schematic systems. (shrink)

The human soul is for pre-modern philosophers the cause of both thinking and life. This double aspect of the soul, which makes man a rational animal, expresses itself above all in human action. Deadly Thought: 'Hamlet' and the Human Soul traces Hamlet's famous inability to act to his inability to hold together these twin aspects of the soul.

This book deals with the history of the problem whether or not time can fully exist without the mind. This has been a vital issue in the philosophy of time, with intriguing arguments and solutions, from Aristotle to the present.

What I call the active mind approach revolves around the claim that what is “on” a person’s mind is in an important sense brought on and held on to through the agent’s self-conscious rational activ...

Hilbert's axiomatization program of physical theories met an interesting challenge when it confronted the rise of quantum mechanics in the mid-twenties. The novelty of the mathematical apparatus of the then newly born theory was to be matched only by its substantial lack of any definite physical interpretation. The early attempts at axiomatization, which are described here, reflect all the difficulty of the task faced by Jordan, Hilbert, von Neumann and others. The role of von Neumann is examined in considerable detail (...) as he can be viewed here as the most outstanding of Hilbert's heirs. Von Neumann, especially in his work devoted to the proof of the impossibility of hidden variables, not only continued Hilbert's program but pushed it to its very limits, blending axiomatic rigor and interpretative commitment. (shrink)

Software systems play an ever more important role in our lives and software engineers and their companies find themselves in a position where they are held responsible for ethical issues that may arise. In this paper, we try to disentangle ethical considerations that can be performed at the level of the software engineer from those that belong in the wider domain of business ethics. The handling of ethical problems that fall into the responsibility of the engineer has traditionally been addressed (...) by the publication of Codes of Ethics and Conduct. We argue that these Codes are barely able to provide normative orientation in software development. The main contribution of this paper is, thus, to analyze the normative features of Codes of Ethics in software engineering and to explicate how their value-based approach might prevent their usefulness from a normative perspective. Codes of Conduct cannot replace ethical deliberation because they do not and cannot offer guidance because of their underdetermined nature. This lack of orientation, we argue, triggers reactive behavior such as “cherry-picking,” “risk of indifference,” “ex-post orientation,” and the “desire to rely on gut feeling.” In the light of this, we propose to implement ethical deliberation within software development teams as a way out. (shrink)

Notes on the life of Adolf Lindenbaum, a complete bibliography of his published works, and selected references to his unpublished results.

The Access principle places an epistemic restriction on our obligations. This principle falls prey to the ‘Shirker Problem’, namely that shirkers could evade their obligations by evading certain epistemic circumstances. To block this problem, it has been suggested that shirkers have the obligation to learn their obligations. This solution yields a regress, yet it is controversial what the moral of the regress actually is. The aim of this paper is two-fold. First, I spell out this intricate dispute. Second, on the (...) basis of my analyses I propose solutions to the Shirker Problem. (shrink)

Ukazano relacje Polaków dotyczące przyrody południowoafrykańskiej z perspektywy ponad 400 lat. Afryka Południowa, praktycznie do naszych czasów, jawiła się im zawsze jako kraj nie tylko bardzo odległy, ale też egzotyczny i interesujący. Determinowało to w poważnym stopniu charakter relacji. Podkreślały one przede wszystkim różnorodność i bogactwo przyrody południowoafrykańskiej. Przyrodę południowoafrykańską postrzegano również przez pryzmat wielkich możliwości łowieckich. Wielu Polaków odwiedzających Afrykę Południową wyrażało zdziwienie z obecności w tym kraju dwóch wykluczających się w zasadzie światów – nietkniętej przyrody i cywilizacji (...) europejskiej. Najczęściej opisywanym miejscem Afryki Południowej był Przylądek Dobrej Nadziei oraz okolice dzisiejszego Kapsztadu. Pierwszego dokładnego zapisu interior dokonał Antoni Rehman w latach siedemdziesiątych XIX wieku. Rzeczowo i ze znawstwem pisali o przyrodzie południowoafrykańskiej polscy uczeni, którzy uczestniczyli w XV Międzynarodowym Kongresie Geologicznym w Pretorii w 1929 roku: Walery Goetel, Jan Lewiński, Józef Morozewicz i Jerzy Loth. Dość liczne relacje odnośnie przyrody południowoafrykańskiej pojawiły się współcześnie w kontekście złożonej sytuacji społeczno- politycznej Afryki Południowej. (shrink)

Extensionalist theories of the specious present suggest that every perceptual experience is extended in time for a short while, such that they are co-extensive in time with the time experienced in them. Thus, there can be no experience of time, unless the experience itself is extended in time. Accordingly, there must be something that unites the temporal parts of a perceptual experience into temporally extended wholes. I call this the “glue-problem for extensionalism”. In this paper I suggest three desiderata that (...) an extensionalist theory should meet in order to solve the glue-problem. I also distinguish between different versions of extensionalism, and argue that none of them can solve the glue-problem without violating at least one desideratum. (shrink)

What's wrong with joining corona parties? In this article, I defend the idea that reasons to avoid such parties come in degrees. I approach this issue from a participation-based perspective. Specifically, I argue that the more people are already joining the party, and the more likely it is that the virus will spread among everyone, the stronger the participation-based reason not to join. In defense of these degrees, I argue that they covary with the expression of certain attitudes.

In this encyclopedia entry I canvass the current interpretations of John Locke's concept of Real Essence and the role it plays in his philosophy.

The quantum-relativistic breakthrough in physics has radically changed the scientific worldview. Several basic intuitions, which underlie traditional philosophy of nature, has been abandoned. As a result of this fact, scientists started to pronounce themselves as the highest authority in the philosophy of nature, leaving for the philosophers only the role of commentators. However, it is not physical theories, but their certain interpretations, or disinterpretations, which contradict common intuitions. In the case of relativistic theory, there is an alternative interpretation which allows (...) us to reconcile its content with pre-relativistic intuitions. Therefore it suggest that we should be critical also to other alleged consequences of the „new physics”. (shrink)

In this article I am dealing mainly with the following notions: “perception apparatus” (Weltbildapparat), “view of the world” (Weltbild, picture of the world) and “representation”. The first and the second ones belong to the basic notions in the vocabulary of K. Lorenz’s evolutionary epistemology, the third in cognitive sciences. I seek to demonstrate the relationships between them. This analysis is put in a broader context, indicating the relationships between expensively developing cognitive sciences and evolutionary epistemology (much less popular today). It (...) is quite easy to determine what the perception apparatus is, however, it is harder to state what the view of the world, especially in its ontological aspect, is. Nevertheless, the view of the representation in the context of evolutionary epistemology points to the fact that this notion is still unclear and many representational features can be assigned to objects which, as it seems, are not representations according to cognitive sciences. (shrink)

This volume reflects Jacques Derrida's engagement in the late 1970s with French political debates on the teaching of philosophy and the reform of the French university system. He was a founding member of the Research Group on the Teaching of Philosophy, an activist group that mobilized opposition to the Giscard government's proposals to "rationalize" the French educational system in 1975, and a convener of the Estates General of Philosophy, a vast gathering in 1979 of educators from across France. While addressing (...) specific contemporary political issues on occasion, thus providing insight into the pragmatic deployment of deconstructive analysis, the essays deal mainly with much broader concerns. With his typical rigor and spark, Derrida investigates the genealogy of several central concepts which any debate about teaching and the university must confront. Thus there are essays on the "teaching body," both the faculty _corps_ and the strange interplay in the French tradition between the mind and body of the professor; on the question of age in teaching, analyzed through a famous letter of Hegel; on the class, the classroom, and the socio-economic concept of class in education; on language, especially so-called "natural languages" like French; and on the legacy of the revolutionary tradition, the Estates General, in the university. The essays are linked by the extraordinary care and precision with which Derrida undertakes a political intervention into, and a philosophical analysis of, the institutionalization of philosophy in the university. (shrink)

In this paper, I mainly pursue the following two goals: on the one hand, I want to show how a central Fregean insight is tried to be captured within a two-dimensional strategy. On the other hand, I want to show that, in the light of Saul Kripke’s arguments against descriptivism, this strategy is faced with a fundamental problem. I proceed in four steps: in a first step, I bring together the passages that contain a central Fregean insight as a source (...) of inspiration for a two-dimensional reconstruction and that suggest a descriptivist reading of Frege’s view. In a second step, I shortly present Kripke’s threefold argumentation against two versions of descriptivism, which is also the basis for Kripke’s view that proper names are rigid designators. In a third step, I explain the basic idea of a Frege-inspired two-dimensional strategy which is used to reconcile theories of definite descriptions with theories of rigid designation and which is sometimes characterized as ‘neo-descriptivism’. Since the two-dimensional strategy is dependent on rigidified definite descriptions, I argue, in a fourth step, that, in the light of Kripke’s epistemological and semantic arguments, the two-dimensional strategy is problematic and untenable – though it is, nevertheless, motivated by Kripke’s modal argument. (shrink)

Tibetan Buddhist writings frequently state that many of the things we perceive in the world are in fact illusory, as illusory as echoes or mirages. In Twelve Examples of Illusion , Jan Westerhoff offers an engaging look at a dozen illusions--including magic tricks, dreams, rainbows, and reflections in a mirror--showing how these phenomena can give us insight into reality. For instance, he offers a fascinating discussion of optical illusions, such as the wheel of fire (the "wheel" seen when a torch (...) is swung rapidly in a circle), discussing Tibetan explanations of this phenomenon as well as the findings of modern psychology, and significantly clarifying the idea that most phenomena--from chairs to trees--are similar illusions. The book uses a variety of crystal-clear examples drawn from a wide variety of fields, including contemporary philosophy and cognitive science, as well as the history of science, optics, artificial intelligence, geometry, economics, and literary theory. Throughout, Westerhoff makes both Buddhist philosophical ideas and the latest theories of mind and brain come alive for the general reader. -/- "This delightful book offers a rich and satisfying philosophical feast to anyone interested in the phenomenon of illusion itself or in the Buddhist analysis of the human condition. Westerhoff draws together classical Buddhist scholarship, contemporary cognitive science and his own judicious philosophical reflection in a serious but refreshingly accessible engagement with the Buddhist tradition in the exploration of the role of illusion in our cognitive and emotional lives." Jay L. Garfield, author of Fundamental Wisdom of the Middle Way: Nagarjuna's Mulamadhyamakakarika -/- "Jan Westerhoff creatively juxtaposes an important Buddhist study of illusion with fascinating modern researches on illusory experiences, using the latter to illuminate the former. The result is a revealing account of the pervasiveness of illusion in our cognitive experience and the very structure of our cognitive apparatus. It brings to life the Buddhist discussion of illusion, making it relevant to our everyday experience instead of being high-minded intellectual exercises only." -/- Tao Jiang, author of Contexts and Dialogue: Yogacara Buddhism and Modern Psychology on the Subliminal Mind -/- "The twelve similes for the illusory nature of this world are very profound, and Westerhoff does them wonderful justice in this excellent book." -/- Robert Thurman, Jey Tsong Khapa Professor of Buddhist Studies, Columbia University. (shrink)

The paper addresses a question concerning George Ellis’s theory of top-down causation by considering a challenge to the “level-picture of nature” which he employs as a foundational element in his theory. According to the level-picture, nature is ordered by distinct and finitely many levels, each characterised by its own types of entities, relations, laws and principles of behavior, and causal relations to their respective neighbouring top- and bottom-level. The branching hierarchy that results from this picture enables Ellis to build his (...) model of modular hierarchical structure for complexity, his account of same-level, bottom-up and top-down causation, of emergence, equivalence-classes and multiple realisability. The three main arguments for the level-picture in Ellis’s works are reconstructed and shown to face serious problems. Finally, the paper presents a possible solution to this challenge by introducing a reformulation of certain fundamental points of Ellis’s theory that does without the level-picture of nature. This allows us to preserve all of his central claims about the model of complexity, the three types of causation, emergence, equivalence-classes and multiple realisability. Any problems pertaining to the level-picture can be remedied in the context of Ellis’s theory of top-down causation. (shrink)

Digitization of a health record changes its accessibility. An electronic health record (EHR) can be accessed by multiple authorized users. Health information from EHRs contributes to learning healthcare systems’ development. The objective of this systematic review is to answer a question: What are ethical issues concerning research using EHRs in the literature? We searched Medline Ovid, Embase and Scopus for publications concerning ethical issues of research use of EHRs. We employed the constant comparative method to retrieve common ethical themes. We (...) descriptively summarized empirical studies. The study reveals the breadth, depth, and complexity of ethical problems associated with research use of EHRs. The central ethical question that emerges from the review is how to manage access to EHRs. Managing accessibility consists of interconnected and overlapping issues: streamlining research access to EHRs, minimizing risk, engaging and educating patients, as well as ensuring trustworthy governance of EHR data. Most of the ethical problems concerning EHR-based research arise from rapid cultural change. The framing of concepts of privacy, as well as individual and public dimensions of beneficence, are changing. We are currently living in the middle of this transition period. Human emotions and mental habits, as well as laws, are lagging behind technological developments. In the medical tradition, individual patient’s health has always been in the center. Transformation of healthcare care, its digitalization, seems to have some impacts on our perspective of health care ethics, research ethics and public health ethics. (shrink)

An inquiry into the bioethical or ethical component of post-humanism can be through the question of sex. Following from Manoj’s idea of a cyborg as having a “sexless” possibility, this paper presents other arguments that advance the possibility of asexuality in the posthuman. First, I begin with a discussion of Žižek’s point concerning the cessation or voiding of sexual difference. Second, I will continue such an argument through the selfreplicating possibilities of cloning and full cyberspace immersion, the later as prototyped (...) by Pokémon. And finally, there seems to be an inevitable thread that begs to link the concept of the posthuman to Nietzsche; so I will explore some of the arguments that include or exclude Nietzschean ethics in this prospect. (shrink)