Notoriously, the Einstein equations of general relativity have solutions in which closed timelike curves occur. On these curves time loops back onto itself, which has exotic consequences: for example, traveling back into one's own past becomes possible. However, in order to make time travel stories consistent constraints have to be satisfied, which prevents seemingly ordinary and plausible processes from occurring. This, and several other "unphysical" features, have motivated many authors to exclude solutions with CTCs from consideration, (...) e.g. by conjecturing a chronology protection law. In this contribution we shall investigate the nature of one particular class of exotic consequences of CTCs, namely those involving unexpected cases of indeterminism or determinism. Indeterminism arises even against the backdrop of the usual deterministic physical theories when CTCs do not cross spacelike hypersurfaces outside of a limited CTC-region|such hypersurfaces fail to be Cauchy surfaces. We shall compare this CTC-indeterminism with four other types of indeterminism that have been discussed in the philosophy of physics literature: quantum indeterminism, the indeterminism of the hole argument, non-uniqueness of solutions of differential equations and lack of predictability due to insuffcient data. By contrast, a certain kind of determinism appears to arise when an indeterministic theory is applied on a CTC: things cannot be different from what they already were. Again we shall make comparisons, this time with other cases of determination in physics. We shall argue that on further consideration both this indeterminism and determinism on CTCs turn out to possess analogues in other, familiar areas of physics. CTC- indeterminism is close to the epistemological indeterminism we know from statistical physics, while the "fixedness" typical of CTC-determinism is pervasive in physics. CTC- determinism and CTC-indeterminism therefore do not provide incontrovertible grounds for rejecting CTCs as conceptually inadmissible. (shrink)

We address the question of whether it is possible to operate a time machine by manipulating matter and energy so as to manufacture closed timelike curves. This question has received a great deal of attention in the physics literature, with attempts to prove no- go theorems based on classical general relativity and various hybrid theories serving as steps along the way towards quantum gravity. Despite the effort put into these no-go theorems, there is no widely accepted definition (...) of a time machine. We explain the conundrum that must be faced in providing a satisfactory definition and propose a resolution. Roughly, we require that all extensions of the time machine region contain closed timelike curves; the actions of the time machine operator are then sufficiently "potent" to guarantee that closed timelike curves appear. We then review no-go theorems based on classical general relativity, semi-classical quantum gravity, quantum field theory on curved spacetime, and Euclidean quantum gravity. Our verdict on the question of our title is that no result of sufficient generality to underwrite a confident "yes" has been proven. Our review of the no-go results does, however, highlight several foundational problems at the intersection of general relativity and quantum physics that lend substance to the search for an answer. (shrink)

This paper explores the physical and metaphysical implications of time travel, focusing on the possibility of changing the past, through a comparative analysis of David Lewis' modal realism and Everett's many-worlds interpretation of quantum mechanics. The existence of closed timelike curves (CTCs) in certain solutions to Einstein's field equations provides a theoretical basis for the possibility of backwards time travel, but this leads to a range of paradoxes, most notably the grandfather paradox. David Lewis argues that time (...) travel must maintain consistency and that the past cannot be changed, even if time travel were possible. His view is supported by his modal realism, which posits the existence of a plurality of possible worlds. In contrast, Everett's many-worlds interpretation, which holds that quantum mechanics describes a multiverse of branching realities, might seem to allow for the possibility of multiple, inconsistent histories. By examining these two ontological frameworks, this paper aims to shed light on the paradoxes of time travel and to explore whether the many-worlds interpretation provides a more satisfactory resolution to these paradoxes than Lewis' modal realism. It is argued that while Lewis' view provides a coherent model for maintaining consistency in time travel, Everett's interpretation may offer a more physically grounded and philosophically compelling account of the metaphysics of time travel. The paper concludes by suggesting that the many-worlds interpretation, by locating the branching of timelines within the structure of quantum mechanics itself, may provide a more promising framework for understanding the possibility and implications of time travel than Lewis' modal realism. However, significant questions remain about the nature of personal identity and free will in a branching multiverse. This comparative analysis aims to contribute to the ongoing debate about the metaphysical possibility of time travel and to highlight the value of engaging with interpretations of quantum mechanics in this context. Keywords: time travel, closed timelike curves, modal realism, many-worlds interpretation, grandfather paradox, metaphysics of time. (shrink)

Closed time-like curves (CTCs) naturally appear in a variety of chronology-violating space{times. In these space{times, the principle of self-consistency demands a harmony between local and global a airs that excludes grandfather-like paradoxes. However, selfexisting objects trapped in CTCs are not seemingly avoided by the standard interpretation of this principle, usually constrained to a dynamical framework. In this letter we discuss whether we are committed to accept an ontology with self-existing objects if CTCs actually occur in the universe. In (...) addition, the epistemological status of the principle of self-consistency is analyzed and a discussion on the information flux through CTCs is presented. (shrink)

Gödel's Philosophical Legacy Kurt Gödel's contributions to philosophy extend beyond his incompleteness theorems. He engaged deeply with the work of other philosophers, including Immanuel Kant and Edmund Husserl, and explored topics such as the nature of time, the structure of the universe, and the relationship between mathematics and reality. Gödel's philosophical writings, though less well-known than his mathematical work, offer rich insights into his views on the nature of existence, the limits of human knowledge, and the interplay between the finite (...) and the infinite. His work continues to inspire and challenge philosophers, mathematicians, and scientists, inviting them to explore the profound and often enigmatic questions at the heart of human understanding. -/- Kurt Gödel's Broader Contributions to Philosophy Kurt Gödel, while primarily known for his monumental incompleteness theorems, made significant contributions that extended beyond the realm of mathematical logic. His philosophical pursuits deeply engaged with the works of eminent philosophers like Immanuel Kant and Edmund Husserl. Gödel's explorations into the nature of time, the structure of the universe, and the relationship between mathematics and reality reveal a profound and multifaceted intellectual legacy. -/- Engagement with Immanuel Kant Gödel held a deep interest in the philosophy of Immanuel Kant. He admired Kant's critical philosophy, particularly the distinction between the noumenal and phenomenal worlds. Kant posited that human experience is shaped by the mind’s inherent structures, leading to the conclusion that certain aspects of reality (the noumenal world) are fundamentally unknowable. Gödel’s incompleteness theorems echoed this Kantian theme, illustrating the limits of formal systems in capturing the totality of mathematical truth. Gödel believed that mathematical truths exis t independently of human thought, akin to Kant's noumenal realm. This philosophical alignment provided a robust foundation for Gödel's Platonism, which asserted the existence of mathematical objects as real, albeit abstract, entities. -/- Influence of Edmund Husserl Gödel was also profoundly influenced by Edmund Husserl, the founder of phenomenology. Husserl's phenomenology emphasizes the direct investigation and description of phenomena as consciously experienced, without preconceived theories about their causal explanation. Gödel saw Husserl's work as a pathway to bridge the gap between the abstract world of mathematics and concrete human experience. Husserl's ideas about the structures of consciousness and the intentionality of thought resonated with Gödel's views on mathematical intuition. Gödel believed that human minds could access mathematical truths through intuition, a concept that draws on Husserlian phenomenological methods. -/- The Nature of Time and the Universe Gödel's philosophical inquiries extended to the nature of time and the structure of the universe. His collaboration with Albert Einstein at the Institute for Advanced Study led to the development of the "Gödel metric" in 1949. This solution to Einstein's field equations of general relativity described a rotating universe where time travel to the past was theoretically possible. Gödel's model challenged conventional notions of time and causality, suggesting that the universe might have a more intricate structure than previously thought. Gödel's exploration of time was not just a mathematical curiosity but a profound philosophical statement about the nature of reality. He questioned whether time was an objective feature of the universe or a construct of human consciousness. His work hinted at a timeless realm of mathematical truths, aligning with his Platonist view. -/- Mathematics and Reality Gödel's philosophical outlook extended to the broader relationship between mathematics and reality. He believed that mathematics provided a more profound insight into the nature of reality than empirical science. For Gödel, mathematical truths were timeless and unchangeable, existing independently of human cognition. This perspective led Gödel to critique the materialist and mechanistic views that dominated 20th-century science and philosophy. He argued that a purely physicalist interpretation of the universe failed to account for the existence of abstract mathematical objects and the human capacity to understand them. Gödel's philosophy suggested a more integrated view of reality, where both physical and abstract realms coexist and inform each other. -/- Gödel's Exploration of Time Kurt Gödel, one of the most profound logicians of the 20th century, ventured beyond the confines of mathematical logic to explore the nature of time. His inquiries into the concept of time were not merely theoretical musings but were grounded in rigorous mathematical formulations. Gödel's exploration of time challenged conventional views and opened new avenues of thought in both physics and philosophy. -/- Gödel and Einstein Gödel’s interest in the nature of time was significantly influenced by his friendship with Albert Einstein. Both were faculty members at the Institute for Advanced Study in Princeton, where they engaged in deep discussions about the nature of reality, time, and space. Gödel's exploration of time culminated in his solution to Einstein's field equations of general relativity, known as the Gödel metric. -/- The Gödel Metric In 1949, Gödel presented a model of a rotating universe, which became known as the Gödel metric. This solution to the equations of general relativity depicted a universe where time travel to the past was theoretically possible. Gödel’s rotating universe contained closed timelike curves (CTCs), paths in spacetime that loop back on themselves, allowing for the possibility of traveling back in time. The Gödel metric posed a significant philosophical challenge to the conventional understanding of time. If time travel were possible, it would imply that time is not linear and absolute, as commonly perceived, but rather malleable and subject to the geometry of spacetime. This raised profound questions about causality, the nature of temporal succession, and the very structure of reality. -/- Philosophical Implications Gödel’s exploration of time extended beyond the mathematical implications to broader philosophical inquiries: Nature of Time: Gödel questioned whether time was an objective feature of the universe or a construct of human consciousness. His work suggested that our understanding of time as a linear progression from past to present to future might be an illusion, shaped by the limitations of human perception. -/- Causality and Free Will: The existence of closed timelike curves in Gödel’s model raised questions about causality and free will. If one could travel back in time, it would imply that future events could influence the past, potentially leading to paradoxes and challenging the notion of a deterministic universe. -/- Temporal Ontology: Gödel's work contributed to debates in temporal ontology, particularly the debate between presentism (the view that only the present exists) and eternalism (the view that past, present, and future all equally exist). Gödel’s rotating universe model seemed to support eternalism, suggesting a block universe where all points in time are equally real. Philosophy of Science: Gödel’s exploration of time had implications for the philosophy of science, particularly in the context of understanding the limits of scientific theories. His work underscored the importance of considering philosophical questions when developing scientific theories, as they shape our fundamental understanding of concepts like time and space. -/- Legacy Gödel’s exploration of time remains a significant and controversial contribution to both physics and philosophy. His work challenged established notions and encouraged deeper inquiries into the nature of reality. Gödel’s rotating universe model continues to be a topic of interest in theoretical physics and cosmology, inspiring new research into the nature of time and the possibility of time travel. In philosophy, Gödel’s inquiries into time have prompted ongoing debates about the nature of temporal reality, the relationship between mathematics and physical phenomena, and the limits of human understanding. His work exemplifies the intersection of mathematical rigor and philosophical inquiry, demonstrating the profound insights that can emerge from such an interdisciplinary approach. The Temporal Ontology of Kurt Gödel Kurt Gödel's profound contributions to mathematics and logic extend into the realm of temporal ontology—the philosophical study of the nature of time and its properties. Gödel's insights challenge conventional perceptions of time and suggest a more intricate, layered understanding of temporal reality. This essay explores Gödel's contributions to temporal ontology, particularly through his engagement with relativity and his philosophical reflections. -/- Gödel's Rotating Universe One of Gödel’s most notable contributions to temporal ontology comes from his work in cosmology, specifically his solution to Einstein’s field equations of general relativity, known as the Gödel metric. Introduced in 1949, the Gödel metric describes a rotating universe with closed timelike curves (CTCs). These curves imply that, in such a universe, time travel to the past is theoretically possible, presenting a significant challenge to conventional views of linear, unidirectional time. -/- Implica tions for Temporal Ontology Gödel's rotating universe model has profound implications for our understanding of time: Eternalism vs. Presentism: Gödel’s model supports the philosophical stance known as eternalism, which posits that past, present, and future events are equally real. In contrast to presentism, which holds that only the present moment exists, eternalism suggests a "block universe" where time is another dimension like space. Gödel’s rotating universe, with its CTCs, reinforces this view by demonstrating that all points in time could, in principle, be interconnected in a consistent manner. Non-linearity of Time: The possibility of closed timelike curves challenges the idea of time as a linear sequence of events. In Gödel’s universe, time is not merely a straight path from past to future but can loop back on itself, allowing for complex interactions between different temporal moments. This non-linearity has implications for our understanding of causality and the nature of temporal succession. Objective vs. Subjective Time: Gödel’s work invites reflection on the distinction between objective time (the time that exists independently of human perception) and subjective time (the time as experienced by individuals). His model suggests that our subjective experience of a linear flow of time may not correspond to the objective structure of the universe. This raises questions about the relationship between human consciousness and the underlying temporal reality. -/- Gödel and Philosophical Reflections on Time Gödel’s engagement with temporal ontology was not limited to his cosmological work. He also reflected deeply on philosophical questions about the nature of time and reality, drawing on the ideas of other philosophers and integrating them into his own thinking. Kantian Influences: Gödel was influenced by Immanuel Kant’s distinction between the noumenal world (things as they are in themselves) and the phenomenal world (things as they appear to human observers). Gödel’s views on time echoed this distinction, suggesting that our perception of time might be a phenomenon shaped by the limitations of human cognition, while the true nature of time (the noumenal aspect) might be far more complex and non-linear. Husserlian Phenomenology: Gödel’s interest in Edmund Husserl’s phenomenology also informed his views on time. Husserl’s emphasis on the structures of consciousness and the intentionality of thought resonated with Gödel’s belief in the importance of intuition in accessing mathematical truths. Gödel’s reflections on time incorporated a phenomenological perspective, considering how temporal experience is structured by human consciousness. Mathematical Platonism: Gödel’s Platonist views extended to his understanding of time. Just as he believed in the independent existence of mathematical objects, Gödel saw time as an objective entity with a structure that transcends human perception. His work on the Gödel metric can be seen as an attempt to uncover this objective structure, revealing the deeper realities that underlie our experience of time. (shrink)

The topic is time travel of the sort depicted in H. G. Wells’ classic novel, The Time Machine—Wellsian time travel. The range of proper applicability of the concept of Wellsian time travel is investigated. The results of this investigation are applied to provide a new argument against the metaphysical possibility of time travel in absolute time. Alternatively, the argument is against the possibility of Wellsian time travel relative to a single temporal frame of reference. The argument leaves open the prospect (...) that an object nontrivially moves relative to one temporal reference frame from one time to another relative to another temporal reference frame. The argument does not turn on closed timelike curves or “causal loops” of any kind. It does however invoke the prospect of backward causation—a consequence of backward time travel in conjunction with common sense—but it invokes this possibility only in the weak sense of mere logical consistency. (shrink)

I have defended the idea that the passage of time can be thought of as a local phenomenon, as the succession of causal diamonds along timelike curves, in relativistic spacetimes. This idea has been criticized by Craig Callender and Oliver Pooley. In this paper, I articulate my view in more detail than I have hitherto and defend it from their criticisms.

I have defended the idea that the passage of time can be thought of as a local phenomenon, as the succession of causal diamonds along timelike curves, in relativistic spacetimes. This idea has been criticized by Craig Callender and Oliver Pooley. In this paper, I articulate my view in more detail than I have hitherto and defend it from their criticisms.

The Kripke/Wittgenstein paradox and Goodman’s riddle of induction can be construed as problems of multiple redescription, where the relevant sceptical challenge is to provide factual grounds justifying the description we favour. A choice of description or predicate, in turn, is tantamount to the choice of a curve over a set of data, a choice apparently governed by implicitly operating constraints on the relevant space of possibilities. Armed with this analysis of the two paradoxes, several realist solutions of Kripke’s paradox are (...) examined that appeal to dispositions or other non-occurrent properties. It is found that all neglect crucial epistemological issues: the entities typically appealed to are not observational and must be inferred on the basis of observed entities or events; yet, the relevant sceptical challenge concerns precisely the factual basis on which this inference is made and the constraints operating on it. All disposition ascriptions, the thesis goes on to argue, contain elements of idealization. To ward off the danger of vacuity resulting from the fact that any disposition ascription is true under just the right ideal conditions, dispositional theories need to specify limits on legitimate forms of idealization. This is best done by construing disposition ascriptions as forms of (implicit) curve-fitting, I argue, where the “data” is not necessarily numeric, and the “curve” fitted not necessarily graphic. This brings us full circle: Goodman’s and Kripke’s problems are problems concerning curve-fitting, and the solutions for it appeal to entities the postulation of which is the result of curve-fitting. The way to break the circle must come from a methodology governing the idealizations, or inferences to the best idealization, that are a part of curve-fitting. The thesis closes with an argument for why natural science cannot be expected to be of much help in this domain, given the ubiquity of idealization. (shrink)

As touch remains commonly defined by the closeness it physically implies and it rhetorically evokes, the mere notion of distant touch and of distal haptic perception seems peculiar. But Aristotle’s perspective, which I wish to take as a point of departure, is firm: we perceive the objects of touch, the hot and the cold, the hard and the soft, the curved and the sharp, through other things: δι' ἑτέρων. In this article, I would like to explore this ἕτερος by showing (...) how the otherness of perception always implies an intermediary, a middle point (μέσος), i.e. an other not so other, an other that is able to translate the much more distant otherness of the perceived object. To explore these forgotten layers of alterity that fall into what we commonly conceive of as the impalpable emptiness of distance, I propose to study the idea of distant touch from the perspective of phenomenological aesthetics. In order to do so, I will first examine some aspects of the Husserlian account of perception and will then focus on the phenomenology of distant touch in Alejandra Costamagna’s novel El Sistema del Tacto [The System of Touch] (2018). (shrink)

We present a rigorous way to evaluate the visual perception of correlation in scatterplots, based on classical psychophysical methods originally developed for simple properties such as brightness. Although scatterplots are graphically complex, the quantity they convey is relatively simple. As such, it may be possible to assess the perception of correlation in a similar way. Scatterplots were each of 5.0 extent, containing 100 points with a bivariate normal distribution. Means were 0.5 of the range of the points, and standard deviations (...) 0.2 of this range. Precision was determined via an adaptive algorithm to find the just noticeable differences (jnds) in correlation, i.e., the difference between two side-by-side scatterplots that could be discriminated 75% of the time. Accuracy was measured by direct estimation, using reference scatterplots with fixed upper and lower values, with a test scatterplot adjusted so that its correlation appeared to be halfway between these. This process was recursively applied to yield several further estimates. Results of the discrimination tests show jnd(r) = k (1/b – r), where r is the Pearson correlation, and parameters 0 < k, b < 1. Integration yields a subjective estimate of correlation g(r) = ln(1 – br) / ln(1– b). The values of b found via discrimination closely match those found via direct estimation. As such, it appears that the perception of correlation in a scatterplot is completely described by two related performance curves, specified by two easily-measured parameters. (shrink)

By drawing on the philosophy of Bernard Stiegler, the phenomena of mechanical (a.k.a. artificial, digital, or electronic) intelligence is explored in terms of its real significance as an ever-repeating threat of the reemergence of stupidity (as cowardice), which can be transformed into knowledge (pharmacological analysis of poisons and remedies) by practices of care, through the outlook of what researchers describe equivocally as “artificial stupidity”, which has been identified as a new direction in the future of computer science and machine problem (...) solving as well as a new difficulty to be overcome. I weave together of web of “artificial stupidity”, which denotes the mechanic (1), the human (2), or the global (3). With regards to machine intelligence, artificial stupidity refers to: 1a) Weak A.I. or a rhetorical inversion of designating contemporary practices of narrow task-based procedures by algorithms in opposition to “True A.I.”; 1b) the restriction or employment of constraints that weaken the effectiveness of A.I., which is to say a “dumbing-down” of A.I. by intentionally introducing mistakes by programmers for safety concerns and human interaction purposes; 1c) the failure of machines to perform designated tasks; 1d) a lack of a noetic capacity, which is a lack of moral and ethical discretion; 1e) a lack of causal reasoning (true intelligence) as opposed to statistical associative “curve fitting”; or 2) the phenomenon of increasing human “stupidity” or drive-based behaviors, which is considered as the degradation of human intelligence and/or “intelligent human behavior” through technics; and finally, 3) the global phenomenon of increasing entropy due to a black-box economy of closed systems and/or industry consolidation. (shrink)

A condensed summary of the adventures of ideas (1990-2020). Methodology of evolutionary-phenomenological constitution of Consciousness. Vector (BeVector) of Consciousness. Consciousness is a qualitative vector quantity. Vector of Consciousness as a synthesizing category, eidos-prototecton, intentional meta-observer. The development of the ideas of Pierre Teilhard de Chardin, Brentano, Husserl, Bergson, Florensky, Losev, Mamardashvili, Nalimov. Dialectic of Eidos and Logos. "Curve line" of the Consciousness Vector from space and time. The lower and upper sides of the "abyss of being". The existential tension of (...) being. Five reference “points” (existential-extremum) - world events in the evolution of Consciousness from “homo habilis” to “homo sapiens sapiens”. “Prometheus Effect". Inversion and reversion of Сonsciousness. "Open" and "closed" Сonsciousness. Consciousness and Self-Consciousness. Protogeometer: fall in the future, in the "EgoLand". The problem of justification/substantiation of mathematics (knowledge) is an ontological problem. The crisis of ontology and ontological limits of cognition. Ontological structure of space. The project of constructive dialectic ontology. The methodology of dialectical-ontological construction (modeling): conceptual-figure synthesis, total unification of matter, coincidence of ontological opposites, primordial Meta-Axioma and Superprinciple, vector (bivector) of the absolute state (states) of matter (absolute forms of existence). The ontological "celestial triangle" (Plato). Ontological invariants of the Universum and their ontological paths. Ontological and gnoseological dimensions of space. Triune (ontological) space of nine gnoseological dimensions: absolute rest (linear state, "Continuum")+ absolute motion (absolute vortex, "Discretuum") + absolute becoming (absolute wave, "Dis-Continuum"). Primordial generating structure: ontological framework, ontological carcass and ontological foundation. Ontological (structural, cosmic) memory - the semantic core of the conceptual construction of the Universum being as an eternal process of generation of new meanings and structures. Consciousness is an absolute (unconditional) attractor of meanings, a univalent phenomenon of ontological memory, which manifests itself at a certain level of the Universum being. Ontological space-MatterMemory-Ontological time (S-MM-T). Ontological Rhythm and Cycle. The nature and structure of ontological time. Natural (absolute) determinism. (shrink)

The Kalam Cosmological Argument is perhaps the most solid and widely discussed argument for a caused creation of the universe. The usual objections to the argument mainly focus on the second premise. In this paper we discuss the dependency of the first premise on the topological structure of the space-time manifold adopted for the underlying cosmological model. It is shown that in chronology-violating space-times the first premise can also be violated. The chronology-violation, in turn, requires a massive violation of the (...) so-called energy conditions which might have observational effects that are briefly discussed here. Hence, astronomical observations could be relevant for the validity of the metaphysical argument. In this sense, it is possible to talk of “observational theology”. (shrink)

For decades, student ratings of university faculty have been used by administrators in high stakes faculty employment decisions such as tenure, promotion, contract renewal and reappointment, and merit pay. However, virtually no attention has been paid to the ethical questions of using ratings in employment decisions. Instead, the ratings literature is generally limited to psychometric issues such as whether a given student ratings instrument exhibits the statistical properties of reliability and validity. There is no consensus understanding of teaching effectiveness, the (...) very attribute that students are alleged to “evaluate.” What students are actually doing when they complete a ratings form—whether measuring, evaluating, reporting, judging, opining, etc.—remains unsettled in the ratings literature. If ratings are surveys of student satisfaction, they have no logical or ethical connection with teaching expertise. I argue that the administrative use of student ratings in faculty employment decisions violates basic moral principles including nonmaleficence, beneficence, professional autonomy and clinical independence, and multiple aspects of justice including due care, truthfulness, and equitable treatment. These ethical violations rule against any administrative use of student ratings in faculty employment decisions, including the “use with caution in conjunction with other evaluative methods” deployment of student ratings. My conclusion is that such use should be immediately and universally terminated. Formative use of student questionnaires as part of ordinary instructional communication and feedback between instructor and students is a separate issue and outside of the scope of this paper. (shrink)

PARC is an "appended numeral" system of natural deduction that I learned as an undergraduate and have taught for many years. Despite its considerable pedagogical strengths, PARC appears to have never been published. The system features explicit "tracking" of premises and assumptions throughout a derivation, the collapsing of indirect proofs into conditional proofs, and a very simple set of quantificational rules without the long list of exceptions that bedevil students learning existential instantiation and universal generalization. The system can be used (...) with any Copi-style set of inference rules, so it is quite adaptable to many mainstream symbolic logic textbooks. Consequently, PARC may be especially attractive to logic teachers who find Jaskowski/Gentzen-style introduction/elimination rules to be far less "natural" than Copi-style rules. The PARC system is also keyboard-friendly in comparison to the widely adopted Jaskowski-style graphical subproof system of natural deduction, viz., Fitch diagrams and Copi "bent arrow" diagrams. (shrink)

Bayesians often assume, suppose, or conjecture that for any reasonable explication of the notion of simplicity a prior can be designed that will enforce a preference for hypotheses simpler in just that sense. But it is shown here that there are simplicity-driven approaches to curve-fitting problems that cannot be captured within the orthodox Bayesian framework.

Mechanisms for QoS provisioning in communication networks range from flow-based resource reservation schemes, providing QoS guarantees, through QoS differentiation based on reservation aggregation techniques to adaptation of applications, compensating for incomplete reservations. Scalable, aggregation-based reservations can also be combined with adaptations for a more flexible and robust overall QoS provisioning. Adaptation is particularly important in wireless networks, where reservations schemes are more difficult to realize. It is widely accepted that usability of Cellular or Mobile IP can be largely improved if (...) adaptation is incorporated. Adaptation, in turn, depends on coding techniques involved and on user requirements. Those impose certain preferences and ordering relations on QoS hierarchies or degradation paths to be followed along when adaptation is performed. With the advent of MPEG4 coding techniques, more sophisticated adaptation schemes are more likely to be supported in the future. (shrink)

Can green growth policies help protect the environment while keeping the industry growing and infrastructure expanding? The City of Kitakyushu, Japan, has actively implemented eco-friendly policies since 1967 and recently inspired the pursuit of sustainable development around the world, especially in the Global South region. However, empirical studies on the effects of green growth policies are still lacking. This study explores the relationship between road infrastructure development and average industrial firm size with air pollution in the city through the Environmental (...) Kuznets Curve (EKC) hypothesis. Auto-Regressive Distributed Lag (ARDL) and Non-linear Auto-Regressive Distributed Lag (NARDL) methods were applied on nearly 50-years’ time series data, from 1967 to 2015. The results show that the shape of the EKC of industrial growth, measured by average firm size, depends on the type of air pollution: inverted N-shaped relationships with NO2 and CO, and the U-shaped relationships with falling dust particle and Ox. Regarding infrastructure development, on the one hand, our analysis shows a positive effect of road construction on alleviating the amount of falling dust and CO concentration. On the other hand, the emissions of NO2 and Ox are shown to rise when plotted against road construction. The decline of CO emission, when plotted against both industrial growth and road development, indicates that the ruthlessness of the local government in pursuing green growth policies is effective in this case. However, the story is not straightforward when it comes to other air pollutants, which hint at limits in the current policies. The case of Kitakyushu illustrates the complex dynamics of the interaction among policy, industry, infrastructure, and air pollution. It can serve as an important reference point for other cities in the Global South when policies are formed, and progress is measured in the pursuit of a green economy. Finally, as an OECD SDGs pilot city and the leading Asian green-growth city, policymakers in Kitakyushu city are recommended to revise the data policy to enhance the findability and interoperability of data as well as to invest in the application of big data. (shrink)

In this paper, we introduce and study the concept of" neutrosophic closed set" and" neutrosophic continuous function". Possible application to GIS topology rules are touched upon.

The upshot of this article is that dance functions in Irigaray’s work in the following three ways: as (1) a symbol of a more positive comportment for heterosexual relationships; (2) an indication that the ambivalence in Irigaray’s work is self-consciously strategic; and (3) an example that teases apart the concepts of negative and positive mimesis, specifically by fleshing out the latter. More concisely, dance constitutes a figure of positive ambivalence (whether between heterosexual lovers, participants in a philosophical dialogue, or aspects (...) of a concept) as self-mimetic, curved silvering in the pursuit of social justice. (shrink)

According to the structured theory of propositions, if two sentences express the same proposition, then they have the same syntactic structure, with corresponding syntactic constituents expressing the same entities. A number of philosophers have recently focused attention on a powerful argument against this theory, based on a result by Bertrand Russell, which shows that the theory of structured propositions is inconsistent in higher order-logic. This paper explores a response to this argument, which involves restricting the scope of the claim that (...) propositions are structured, so that it does not hold for all propositions whatsoever, but only for those which are expressible using closed sentences of a given formal language. We call this restricted principle Closed Structure, and show that it is consistent in classical higher-order logic. As a schematic principle, the strength of Closed Structure is dependent on the chosen language. For its consistency to be philosophically significant, it also needs to be consistent in every extension of the language which the theorist of structured propositions is apt to accept. But, we go on to show, Closed Structure is in fact inconsistent in a very natural extension of the standard language of higher-order logic, which adds resources for plural talk of propositions. We conclude that this particular strategy of restricting the scope of the claim that propositions are structured is not a compelling response to the argument based on Russell’s result, though we note that for some applications, for instance to propositional attitudes, a restricted thesis in the vicinity may hold some promise. (shrink)

The current debate on closed-loop brain devices (CBDs) focuses on their use in a medical context; possible criminal justice applications have not received scholarly attention. Unlike in medicine, in criminal justice, CBDs might be offered on behalf of the State and for the purpose of protecting security, rather than realising healthcare aims. It would be possible to deploy CBDs in the rehabilitation of convicted offenders, similarly to the much-debated possibility of employing other brain interventions in this context. Although such (...) use of CBDs could in principle be consensual, there are significant differences between the choice faced by a criminal offender offered a CBD in the context of criminal justice, and that faced by a patient offered a CBD in an ordinary healthcare context. Employment of CBDs in criminal justice thus raises ethical and legal intricacies not raised by healthcare applications. This paper examines some of these issues under three heads: autonomy, human rights, and accountability. (shrink)

In this paper, I draw attention to various doctrines common to different Vedāntic traditions. In particular, I pay close attention to the doctrine of beginningless _karman_. I also note that this doctrine seems to stand in tension with Leibnizian Cosmological Arguments (LCAs) and Kalām Cosmological Arguments (KCAs). This tension arises because defenders of these arguments argue that an infinite causal regress or an actual infinite cannot be physically instantiated and because the doctrine of beginningless _karman_ seems to imply that such (...) a regress or actual infinite can be physically instantiated. I address this tension by showing that not all interpretations of beginningless _karman_ involve an infinite causal regress or an actual infinite. I close this paper by highlighting a few features that Vedāntic traditions have that make them more resistant to some objections to LCAs and KCAs. (shrink)

We often think or say that someone was wrong about something but almost right about it or close to the truth. This can mean more than one thing. Here, I propose an analysis of the idea of being epistemically close to the truth. This idea plays an important role in our practice of epistemic evaluation and therefore deserves some detailed attention. I start with an exposition of the idea of getting things right by looking at the main forms of reliabilism (...) about true belief and belief acquisition. The focus on reliabilism is justified because everyone is a reliabilist in a basic sense. Section 2 develops a notion of closeness to the truth in two steps. Section 3 mentions some ways in which this notion is useful, one having to do with the Gettier problem. (shrink)

In this paper I challenge the pernicious aspects of Milton Friedman's methodological outlook that continues to hold sway over mainstream neoclassical economists. I do this by showing how Friedman's own methodological dicta could have been used against him when he famously advanced the expectations critique of the Phillips curve at his presidential address to the American Economic Association. I use this case study to further suggest that psychological and neurophysiological data should not be deemed irrelevant to economic science.

Two principles in epistemology are apparent examples of the close connection between rationality and truth. First, adding a disjunct to what it is rational to believe yields a proposition that’s also rational to believe. Second, what’s likely if believed is rational to believe. While these principles are accepted by many, it turns out that they clash. In light of this clash, we must relinquish the second principle. Reflecting on its rationale, though, reveals that there are two distinct ways to understand (...) the connection between rationality and truth. Rationality is fundamentally a guide to the belief-independent truth, rather than a guide to acquiring true beliefs. And this in turn has important implications for current discussions of permissivism, epistemic reasons, and epistemic consequentialism. (shrink)

Albert Einstein’s theory of General Relativity was once the leading theory in theoretical physics. Unfortunately the theory describes macroscopic reality without a clear link with the the microcosm in respect to the properties of spacetime. However the theory of General Relativity has proved to predict macroscopic phenomena in a very accurate way. Nowadays most theoretical physicists use the conceptual framework of quantum theory. So it is not surprisingly that the question about the “true nature” of spacetime becomes very intrigue.

The developing body of empirical work on the "Gettier effect" indicates that, in general, the presence of a Gettier-type structure in a case makes participants less likely to attribute knowledge in that case. But is that a sufficient reason to diverge from a JTB theory of knowledge? I argue that considerations of good model selection, and worries about noise and overfitting, should lead us to consider that a live, open question. The Gettier effect is perhaps so transient, and so sensitive (...) to other, epistemologically-inappropriate factors, that it raises the question of whether it ought to be counted as something to include in our theories -- or as a piece of noise to be excluded from them. (shrink)

In this chapter, I revisit the issue of the explanatory gap that is supposed to open when considering identity statements between physical and mental phenomena. I show that the question asked in the original formulation of the explanatory gap was this: ʻwhy this phenomenal character, rather than any other, is attached to this physiological process?ʼ I argue that this question can be answered, because there is a natural fit between the phenomenal character of experiences and their functional roles. For example, (...) pains feel inherently unpleasant, and that explains why they cause avoidance behaviour, and the felt location and intensity of pain indicates the location and extent of damage to the body. I discuss some other possible gaps in our understanding the relationship between the mental and the physical, and conclude that the fit between functional role and phenomenal character goes a long way, though probably not the whole way, to closing the explanatory gap. (shrink)

The distinction between true belief and knowledge is one of the most fundamental in philosophy, and a remarkable effort has been dedicated to formulating the conditions on which true belief constitutes knowledge. For decades, much of this epistemological undertaking has been dominated by a single strategy, referred to here as the modal approach. Shared by many of the most widely influential constraints on knowledge, including the sensitivity, safety, and anti-luck/risk conditions, this approach rests on a key underlying assumption — the (...) modal profiles available to known and unknown beliefs are in some way asymmetrical. The first aim of this paper is to deconstruct this assumption, identifying its plausibility with the way in which epistemologists frequently conceptualize human perceptual systems as excluding certain varieties of close error under conditions conducive to knowledge acquisition. The second aim of this paper is to then argue that a neural phase phenomenon indicates that this conceptualization is quite likely mistaken. This argument builds on the previous introduction of this neural phase to the context of epistemology, expanding the use of neural phase cases beyond relatively narrow questions about epistemic luck to a much more expansive critique of the modal approach as a whole. (shrink)

The hole argument purportedly shows that spacetime substantivalism implies a pernicious form of indeterminism. We show that the argument is seductive only because it mistakes a trivial claim (viz. there are isomorphic models) for a significant claim (viz. there are hole isomorphisms). We prove that the latter claim is false -- thereby closing the debate about whether substantivalism implies indeterminism.

Two intuitions lie at the heart of our conception of free will. One intuition locates free will in our ability to deliberate effectively and control our actions accordingly: the ‘Deliberation and Control’ (DC) condition. The other intuition is that free will requires the existence of alternative possibilities for choice: the AP condition. These intuitions seem to conflict when, for instance, we deliberate well to decide what to do, and we do not want it to be possible to act in some (...) other way. I suggest that intuitions about the AP condition arise when we face ‘close calls,’ situations in which, after deliberating, we still do not know what we really want to do. Indeed, several incompatibilists suggest such close calls are necessary for free will. I challenge this suggestion by describing a ‘confident agent’ who, after deliberating, always feels confident about what to do (and can then control her actions accordingly). Because she maximally satisfies the DC condition, she does not face close calls, and the intuition that the AP condition is essential for free will does not seem to apply to her. I conclude that intuitions about the importance of the AP condition rest on our experiences of close calls and arise precisely to the extent that our deliberations fail to arrive at a clear decision. I then raise and respond to several objections to this thought experiment and its relevance to the free will debate. (shrink)

Miranda Fricker’s insightful work on epistemic injustice discusses two forms of epistemic injustice—testimonial injustice and hermeneutical injustice. Hermeneutical injustice occurs when the victim lacks the interpretative resources to make sense of her experience, and this lacuna can be traced down to a structural injustice. In this paper, I provide one model of how to fill the conceptual gap in hermeneutical injustice. First, I argue that the victims possess conceptual resources to make sense of their experiences, namely phenomenal concepts. Second, I (...) show how one might work the way up in a two-step process from a subjective, phenomenal concept to a novel, public concept. Finally, I discuss the conditions that have to be met for this process to be successful. The resulting model shows a way how the victims might alleviate hermeneutical injustice by developing novel concepts, given that the dominant group does not care about their predicament. (shrink)

We consider momentum operators on intrinsically curved manifolds. Given that the momentum operators are Killing vector fields whose integral curves are geodesics, it is shown that the corresponding manifold is either flat, or otherwise of compact type with positive constant sectional curvature and dimension equal to 1, 3 or 7. Explicit representations of momentum operators and the associated Casimir element will be discussed for the 3-sphere. It will be verified that the structure constants of the underlying Lie algebra are (...) proportional to 2ħ/R, where R is the curvature radius of the sphere. This results in a countable energy and momentum spectrum of freely moving particles. It is shown that the maximum resolution of the possible momenta is given by the de-Broglie wave length λ=πR, which is identical to the diameter of the manifold. The corresponding covariant position operators are defined in terms of geodesic normal coordinates and the associated commutator relations of position and momentum are established. (shrink)

This article explores the relationship between friendship and morality. Two ideas have been influential in the history of moral philosophy: the impartial standpoint and close friendship. These two perspectives on thought and action can conflict, however, and such a case is presented here. In an attempt to resolve these tensions, and understand the assumption that gives rise to it, I explore an alternative conception of moral conduct and friendship suggested by early Confucian thought. Within this account, moral conduct is that (...) which aims at harmony, understood as the appropriate blending of different elements. This suggests a conception of friendship that realizes harmony through a focus on shared activities, and the quality of interaction achieved between people as they participate in shared social events. This account offers a novel way of conceptualizing friendship, which also avoids the tension between the impartial standpoint and close friendship. (shrink)

Most mental health research largely ignores or minimises gender and age differences in depression. In ‘Don't mind the gap: Why do we not care about the gender gap in mental health?’, Patalay and Demkowicz identify a dearth of research on the causal factors of depression in young women. They attribute this to an over-reliance on biological accounts of gender differences in depression. Patalay and Demkowicz conclude that a person-centred approach that meaningfully engages with the reports of young women with depression (...) is more likely to expose the social drivers of depression that impact this group. This commentary focuses on Patalay and Demkowicz's call to examine the patient's lived experience. We argue that there is an urgent need to reflect upon the methodologies involved in examining lived experience and how they can be best utilised. Ultimately, we advocate for an approach known as ‘phenomenological psychopathology’, through a phenomenological investigation of depression in young women, we can go some way towards closing the gender gap. (shrink)

This paper examines how time functions as an active subject in the works of Mark Doty and Edmund de Waal, mainly through their reflections on still life and material objects. Doty’s meditations on a still life painting and De Waal’s exploration of his family’s netsuke collection reveal an inversion of our typical understanding of time, where instead of us moving through time, time itself shapes, preserves, or erodes people, places, and things. By closely observing these objects—Doty’s “things of the world” (...) and De Waal’s family heirlooms—each author recognizes how time acts upon them, turning seemingly permanent elements into transient reflections. This study argues that, in both accounts, time is a subjugating force and a silent reminder of impermanence. In this way, the paper invites readers to adopt a “close-looking” perspective, recognizing time’s invisible yet profound impact on memory, materiality, and the passage of life itself. (shrink)

ABSTRACT In his contribution to this issue, “A and B Theories of Closed Time”, Phil Dowe argues that A- and B-theories of time are equally compatible with closed time, though it is commonly supposed that only B-theories are compatible with it. With some reservations to be noted below I agree with Dowe’s general conclusion, but in the course of his argument there are a number of false statements and misrepresentations of detail that require comment. I will not be (...) able to deal with all of them in this brief note. (shrink)

Aristotle rightly holds that the constitution of a city is not entirely captured by its written documents or official political structures. More fundamentally, the constitution of a city is made up of its real and deep habits, customs, relations, expectations, aspirations, and ideals of the people who live there. The aim here is to articulate five values that together constitute what I will call close-knit cities: a) ecological resiliency; b) intimate proximity; c) social heterogeneity; d) fairness; e) social trust. I (...) give a brief account of each of these values alone, along the way showing how each value needs the others to be fully realised, and ultimately argue that at least most cities should aspire to become close-knit cities because they simultaneously realise environmental stewardship and enable human flourishing. (shrink)

Bell-type inequalities are proven using oversimplified probabilistic models and/or counterfactual definiteness (CFD). If setting-dependent variables describing measuring instruments are correctly introduced, none of these inequalities may be proven. In spite of this, a belief in a mysterious quantum nonlocality is not fading. Computer simulations of Bell tests allow people to study the different ways in which the experimental data might have been created. They also allow for the generation of various counterfactual experiments’ outcomes, such as repeated or simultaneous measurements performed (...) in different settings on the same “photon-pair”, and so forth. They allow for the reinforcing or relaxing of CFD compliance and/or for studying the impact of various “photon identification procedures”, mimicking those used in real experiments. Data samples consistent with quantum predictions may be generated by using a specific setting-dependent identification procedure. It reflects the active role of instruments during the measurement process. Each of the setting-dependent data samples are consistent with specific setting-dependent probabilistic models which may not be deduced using non-contextual local realistic or stochastic hidden variables. In this paper, we will be discussing the results of these simulations. Since the data samples are generated in a locally causal way, these simulations provide additional strong arguments for closing the door on quantum nonlocality. (shrink)

This article analyses the processes involved in description and ‘close looking’ in relation to works of art. Aspects discussed include the often-unspoken appeal to a limited form of artistic intention, the use of ‘context’, and the way that pictorial features are manipulated in the service of interpretation. Ultimately the article shows how great a role the writers’ overarching assumptions (such as about the history of modernism) are likely to play in apparently object-focused analysis, and as such why we should be (...) suspicious of claims that artworks might ‘determine their own interpretation’. (shrink)

Several theorists have been attracted to the idea that in order to account for counterpossibles, i.e. counterfactuals with impossible antecedents, we must appeal to impossible worlds. However, few have attempted to provide a detailed impossible worlds account of counterpossibles. Berit Brogaard and Joe Salerno’s ‘Remarks on Counterpossibles’ is one of the few attempts to fill in this theoretical gap. In this article, I critically examine their account. I prove a number of unanticipated implications of their account that end up implying (...) a counterintuitive result. I then examine a suggested revision and point out a surprising implication of the revision. (shrink)

Philosophers from Hart to Lewis, Johnston and Bennett have expressed various degrees of reservation concerning the doctrine of double effect. A common concern is that, with regard to many activities that double effect is traditionally thought to prohibit, what might at first look to be a directly intended bad effect is really, on closer examination, a directly intended neutral effect that is closely connected to a foreseen bad effect. This essay examines the extent to which the commonsense concept of intention (...) supports a reasonably consistent and coherent application of double effect. Two important conclusions are these: (1) a number of traditionally proscribed activities involve a kind of “targeting” of innocents that can be taken to exhibit a direct intention to harm them; (2) a direct intention to harm need not involve a desire to harm in any ordinary sense of the latter expression. (shrink)

In this paper we analyze methodological and philosophical implications of algorithmic aspects of unconventional computation. At first, we describe how the classical algorithmic universe developed and analyze why it became closed in the conventional approach to computation. Then we explain how new models of algorithms turned the classical closed algorithmic universe into the open world of algorithmic constellations, allowing higher flexibility and expressive power, supporting constructivism and creativity in mathematical modeling. As Goedels undecidability theorems demonstrate, the closed (...) algorithmic universe restricts essential forms of mathematical cognition. In contrast, the open algorithmic universe, and even more the open world of algorithmic constellations, remove such restrictions and enable new, richer understanding of computation. (shrink)

I examine the meaning and merits of a premise in the Exclusion Argument, the causal closure principle that all physical effects have physical causes. I do so by addressing two questions. First, if we grant the other premises, exactly what kind of closure principle is required to make the Exclusion Argument valid? Second, what are the merits of the requisite closure principle? Concerning the first, I argue that the Exclusion Argument requires a strong, “stringently pure” version of closure. The latter (...) employs two qualifications concerning the physical sufficiency and relative proximity of the physical cause required for every physical effect. The second question is addressed in two steps. I begin by challenging the adequacy of the empirical support offered by David Papineau for closure. Then I assess the merits of “level” and “domain” versions of stringently pure closure. I argue that a domain version lacks adequate and non-question-begging support within the context of the Exclusion Argument. And I argue that the level version leads to a puzzling metaphysics of the physical domain. Thus, we have grounds for rejecting the version of closure required for the Exclusion Argument. This means we can resist the Exclusion Argument while avoiding the implausible implications that come with rejecting one of its other premises. That is, because there are grounds to reject causal closure, one can reasonably affirm the non-overdeterminative causal efficacy of conscious mental states while denying that the latter are identical with physical states. (shrink)

This paper presents a new system of conditional logic B2, which is strictly intermediate in strength between the existing systems B1 and B3 from John Burgess (1981) and David Lewis (1973a). After presenting and motivating the new system, we will show that it is characterized by a natural class of frames. These frames correspond to the idea that conditionals are about which worlds are nearly closest, rather than which worlds are closest. Along the way, we will also give new characterization (...) results for B1 and B3, along with two other new systems B1.1 and B1.2. (shrink)

Autarchy is an economic system in which the state refuses any commercial connection with the outside, solely relying on its own resources. In an autarchic economy, the state does not participate in the international economic life, is not part of any regional and/or global economic organization and does not export or import goods. The characteristics of a closed, autarchic economy are: 1). the state does not take into account the progress of the world economy, 2). the state lacks involvement (...) in the international economy, 3). economic independence is pursued by drastically reducing or canceling imports and exports, 4). the state solely relies on its own resources. This economic system can lead to: a). a pronounced economic decline, due to the impossibility of the state to provide the necessary goods and services for the population’s livelihood, b). a decrease in national incomes, considerable decrease in GDP, c). an increase in the state’s access to domestic natural resources, which in turn leads to an increased chance of their depletion, d). social instability. (shrink)

Social robots are marketed as human tools promising us a better life. This marketing strategy commodifies not only the labor of care but the caregiver as well, conjuring a fantasy of technoliberal futurism that echoes a colonial past. Against techno-utopian fantasies of a good life as one involving engineered domestic help, I draw here on the techno-dystopian television show Humans (stylized HUMⱯNS) to suggest that we should find our desires for such help unsettling. At the core of my argument is (...) a return of the “uncanny valley” problem, from its reformulation as an engineering/design problem to its origins as a psychosocial symptom of an unresolved, traumatic past. I conclude that our sense of the uncanny may be best understood as a moral capacity that should be honed rather than evaded. (shrink)

I attend to the temporal schema of open/closed by examining its elaboration in Bergson's philosophy and critically parsing the possibilities for its destabilization. Though Bergson wrote in a colonial context, this context barely receives acknowledgement in his work. This obscures the uncomfortable resonances between Bergson's late work, The Two Sources of Morality and Religion, and the temporal narratives that justify French colonialism. Given Bergson's uptake by philosophers, such as Gilles Deleuze, and by contemporary feminist and political theorists (especially “new (...) materialists”), a critical re-examination is called for. The Two Sources not only introduces a new dichotomy into Bergsonian philosophy—that of open/closed—it puts an end to the movement of duration by defining its possibilities as goals already given in advance. By turning the tools of Bergsonian critique onto The Two Sources, I propose an alternative to the open/closed—that of the “half-open”—creating in this way the conditions for decolonizing duration. (shrink)