The gravitational equations were derived in general relativity using the assumption of their covariance relative to arbitrary transformations of coordinates. It has been repeatedly expressed an opinion over the past century that such equality of all coordinate systems may not correspond to reality. Nevertheless, no actual verification of the necessity of this assumption has been made to date. The paper proposes a theory of gravity with a constraint, the degenerate variants of which are general relativity and the unimodular theory of (...) gravity. This constraint is interpreted from a physical point of view as a sufficient condition for the adiabaticity of the process of the evolution of the space–time metric. The original equations of the theory of gravity with the constraint are formulated. On this basis, a unified model of the evolution of the modern, early, and very early Universe is constructed that is consistent with the observational astronomical data but does not require the hypotheses of the existence of dark energy, dark matter or inflatons. It is claimed that: physical time is anisotropic, the gravitational field is the main source of energy of the Universe, the maximum global energy density in the Universe was 64 orders of magnitude smaller the Planckian one, and the entropy density is 18 orders of magnitude higher the value predicted by GR. The value of the relative density of neutrinos at the present time and the maximum temperature of matter in the early Universe are calculated. The wave equation of the gravitational field is formulated, its solution is found, and the nonstationary wave function of the very early Universe is constructed. It is shown that the birth of the Universe was random. (shrink)

The familiar Vendler-Kenny scheme of verb-types, viz., performances (further differentiated by Vedler into accomplishments and achievements), activities, and states, is too narrow in two important respects. First, it is narrow linguistically. It fails to take into account the phenomenon of verb aspect. The trichotomy is not one of verbs as lexical types but of predications. Second, the trichotomy is narrow ontologically. It is a specification in the context of human agency of the more fundamental, topic-neutral trichotomy, event-process-state.The central component in (...) this ontological trichotomy, event, can be sharply differentiated from its two flanking components by adapting a suggestion by Geoffrey N. Leech and others that the contrast between perfective and imperfective aspect in verbs corresponds to the count/mass distinction in the domain of nouns. With the help of two distinctions, of cardinal count adverbials versus frequency adverbials, and of occurrence versus associated occasion, two interrelated criteria for event predication are developed. Accordingly, Mary capsized the boat is an event predication because (a) it is equivalent to There was at least one capsizing of the boat by Mary, or (b) because it admits cardinal count adverbials, e.g., at least once, twice, three times. Ontologically speaking, events are defined as those occurrences that are inherently countable. (shrink)

We show that many principles of first-order arithmetic, previously only known to lie strictly between [Formula: see text]-induction and [Formula: see text]-induction, are equivalent to the well-foundedness of [Formula: see text]. Among these principles are the iteration of partial functions of Hájek and Paris, the bounded monotone enumerations principle by Chong, Slaman, and Yang, the relativized Paris–Harrington principle for pairs, and the totality of the relativized Ackermann–Péter function. With this we show that the well-foundedness of [Formula: see text] is a (...) far more widespread than usually suspected. Further, we investigate the [Formula: see text]-iterated version of the bounded monotone iterations principle, and show that it is equivalent to the well-foundedness of the -height [Formula: see text]-tower [Formula: see text]. (shrink)

This book presents some of the most recent trends and developments in Presocratic scholarship. A wide range of topics are covered - from the metaphysical to the moral to the methodological - as well as a broad a range of authors: from recognized figures such as Heraclitus and Parmenides to Sophistic thinkers whose place has traditionally been marginalized, such as Gorgias and the author of the Dissoi Logoi. Several of the pieces are concerned with the later reception and influence of (...) the Presocratics on ancient philosophy, an area of study important both for the light it sheds on our evidence for Presocratic thought and for understanding the philosophical power of their ideas. Drawing together contributions from distinguished authorities and internationally acclaimed scholars of ancient philosophy, this book offers new challenges to traditional interpretations in some areas of Presocratic philosophy and finds new support for traditional interpretations in other areas. (shrink)

In the work of interpreting Parmenides we have witnessed in the ’sixties and ’seventies, in English language scholarship, that rarest of phenomena in the study of ancient philosophy, the emergence of a consensus. Four interpretive theses now seem quite widely shared: Parmenides deliberately suppresses the subject of esti, “is,” or einai, “to be,” in his statement of the two “routes” in B2, his intention being to allow the subject to become gradually specified as the argument unfolds. The negative route, ouk (...) esti, “is not,” or mē einai, “not to be,” is banned because sentences that adhere to it fail to refer to actual entities—the latter to be understood broadly, as will shortly be stated in thesis. The argument does not depend on a confusion between the “is” of predication and the “is” of existence. In the relevant contexts, esti and einai involve a “fused” or “veridical” use of the verb “to be”; in other words, esti or einai have the force of “is actual” or “obtains,” or “is the case,” envisaging a variable subject x that ranges over states-of-affairs. (shrink)

I am grateful to the editors of the Canadian Journal of Philosophy for inviting me to write a comment on Kathleen Gill’s ‘On the Metaphysical Distinction Between Processes and Events’. I readily concede that she is right in the central criticism she makes of my 1978 paper: that a properly metaphysical or ontological distinction between processes and events, if it is to be made at all, cannot be sustained on the basis of the informal linguistic criteria I offered in ‘Events, (...) Processes, and States.’ My main concern in that paper was to show that discussions of the Kenny-Vendler typology of activities, performances, and states had focused too narrowly on verb types, on adverbial phrases, on the domain of human action, and on English-language intuitions. Mine was one of several voices urging in the late 1970s that issues of tense logic and of the logic of verb types had to be placed in the broader context of verb aspect — a salient and pervasive structure in natural languages generally, and one that had been studied by philologists and linguists since the nineteenth century. Captivated, as I and others had become at the time, by evidence that the distinction between count nouns and mass nouns appears to be mirrored in verb predications, I went on to make some rather venturesome ‘ontological’ claims. It is satisfying, of course, that Gill accepts not only that there is ‘substantial evidence in favor of recognizing a grammatical distinction between the language of processes and [the language of] events’ but also that ‘similarities with count and mass expressions will allow us to apply techniques for han dling nominal expressions to verbal expressions’. It is more than satisfying that the phenomenon of verb aspect is now noticed and investigated by philosophers as well as by linguists. (shrink)

Let the chain antichain principle (CAC) be the statement that each partial order on $\mathbb{N}$ possesses an infinite chain or an infinite antichain. Chong, Slaman, and Yang recently proved using forcing over nonstandard models of arithmetic that CAC is $\Pi^1_1$-conservative over $\text{RCA}_0+\Pi^0_1\text{-CP}$ and so in particular that CAC does not imply $\Sigma^0_2$-induction. We provide here a different purely syntactical and constructive proof of the statement that CAC (even together with WKL) does not imply $\Sigma^0_2$-induction. In detail we show using a (...) refinement of Howard's ordinal analysis of bar recursion that $\text{WKL}_0^\omega+\text{CAC}$ is $\Pi^0_2$-conservative over PRA and that one can extract primitive recursive realizers for such statements. Moreover, our proof is finitary in the sense of Hilbert's program. CAC implies that every sequence of $\mathbb{R}$ has a monotone subsequence. This Bolzano-Weierstraß}-like principle is commonly used in proofs. Our result makes it possible to extract primitive recursive terms from such proofs. We also discuss the Erdős-Moser principle, which—taken together with CAC—is equivalent to $\text{RT}^2_2$. (shrink)

This article discusses Xenophanes' “cloud astro-physics”. It analyses and explains all heavenly and meteorological phenomena in terms of clouds. It provides a view of this newer Xenophanes, who is now being recognized as an important philosopher-scientist in his own right and a crucial figure in the development of critical thought about human knowledge and its objects in the next generation of Presocratic thinkers. Xenophanes' account has been preserved in Aëtius, the doxographic compendium reconstructed by Hermann Diels late in the nineteenth (...) century mainly from two sources that show extensive parallelism: pseudo-Plutarch Placita Philosophorum or Epitome of Physical Opinions ; and Ioannes Stobaeus' Eclogae Physicae or Physical Extracts. In the Stobaeus version, which is also the one printed in the standard edition of the Pre-socratics. (shrink)

A hallmark of intelligent behavior is rationality – the disposition and ability to think analytically to make decisions that maximize expected utility or follow the laws of probability. However, the question remains as to whether rationality and intelligence are empirically distinct, as does the question of what cognitive mechanisms underlie individual differences in rationality. In a sample of 331 participants, we assessed the relationship between rationality and intelligence. There was a common ability underpinning performance on some, but not all, rationality (...) tests. Latent factors representing rationality and general intelligence were strongly correlated (r =.54), but their correlation fell well short of unity. Rationality correlated significantly with fluid intelligence (r =.56), working memory capacity (r =.44), and attention control (r =.49). Attention control fully accounted for the relationship between working memory capacity and rationality, and partially accounted for the relationship between fluid intelligence and rationality. We conclude by speculating about factors rationality tests may tap that other cognitive ability tests miss, and outline directions for further research. (shrink)

We investigate the strength of the existence of a non-principal ultrafilter over fragments of higher-order arithmetic. Let [Formula: see text] be the statement that a non-principal ultrafilter on ℕ exists and let [Formula: see text] be the higher-order extension of ACA0. We show that [Formula: see text] is [Formula: see text]-conservative over [Formula: see text] and thus that [Formula: see text] is conservative over PA. Moreover, we provide a program extraction method and show that from a proof of a strictly (...) [Formula: see text] statement ∀ f ∃ g A qf in [Formula: see text] a realizing term in Gödel's system T can be extracted. This means that one can extract a term t ∈ T, such that ∀ f A qf). (shrink)

The aim of this paper is to determine the logical and computational strength of instances of the Bolzano-Weierstraß principle and a weak variant of it.We show that BW is instance-wise equivalent to the weak König’s lemma for Σ01-trees . This means that from every bounded sequence of reals one can compute an infinite Σ01-0/1-tree, such that each infinite branch of it yields an accumulation point and vice versa. Especially, this shows that the degrees d ≫ 0′ are exactly those containing (...) an accumulation point for all bounded computable sequences.Let BWweak be the principle stating that every bounded sequence of real numbers contains a Cauchy subsequence . We show that BWweak is instance-wise equivalent to the cohesive principle and—using this—obtain a classification of the computational and logical strength of BWweak. Especially we show that BWweak does not solve the halting problem and does not lead to more than primitive recursive growth. Therefore it is strictly weaker than BW. We also discuss possible uses of BWweak. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. (shrink)

In this paper we study with proof-theoretic methods the function(al) s provably recursive relative to Ramsey's theorem for pairs and the cohesive principle (COH). Our main result on COH is that the type 2 functional provably recursive from $RCA_0 + COH + \Pi _1^0 - CP$ are primitive recursive. This also provides a uniform method to extract bounds from proofs that use these principles. As a consequence we obtain a new proof of the fact that $WKL_0 + \Pi _1^0 - (...) CP + COH$ is $\Pi _1^0 $ -conservative over PRA. Recent work of the first author showed that $\Pi _1^0 + CP + COH$ is equivalent to a weak variant of the Bolzano-Weierstraß principle. This makes it possible to use our results to analyze not only combinatorial but also analytical proofs. For Ramsey's theorem for pairs and two colors $\left( {RT_2^2 } \right)$ we obtain the upper bounded that the type 2 functionals provable recursive relative to $RCA_0 + \sum\nolimits_2^0 {IA + RT_2^2 } $ are in T₁. This is the fragment of Gödel's system T containing only type 1 recursion—roughly speaking it consists of functions of Ackermann type. With this we also obtain a uniform method for the extraction of T₁-bounds from proofs that use RT2..... Moreover, this yields a new proof of the fact that $WKL_0 + \sum\nolimits_2^0 {IA} + RT_2^2 $ is $\Pi _1^0 $ -conservative over $RCA_0 + \sum\nolimits_2^0 { - IA} $ . The results are obtained in two steps: in the first step a term including Skolem functions for the above principles is extracted from a given proof. This is done using Gödel's functional interpretation. After this the term is normalized, such that only specific instances of the Skolem functions are used. In the second step this term is interpreted using $\Pi _1^0 $ -comprehension. The comprehension is then eliminated in favor of induction using either elimination of monotone Skolem functions (for COH) or Howard's ordinal analysis of bar recursion (for $RT_2^2 $. (shrink)

Achieving space situational awareness requires, at a minimum, the identification, characterization, and tracking of space objects. Leveraging the resultant space object data for purposes such as hostile threat assessment, object identification, and conjunction assessment presents major challenges. This is in part because in characterizing space objects we reference a variety of identifiers, components, subsystems, capabilities, vulnerabilities, origins, missions, orbital elements, patterns of life, operational processes, operational statuses, and so forth, which tend to be defined in highly heterogeneous and sometimes inconsistent (...) ways. The Space Domain Ontologies are designed to provide a consensus-based realist framework for formulating such characterizations in a way that is both consistent and computable. Space object data are aligned with classes and relations in a suite of ontologies built around the existing Space Object Ontology. They are stored in a dynamically updated Resource Description Framework triple store, which can be queried to support space situational awareness and the needs of spacecraft operators and analysts. This paper provides an overview of the Space Domain Ontologies and their development and use. It presents the motivation for and advantages of the Space Domain Ontologies, including the benefits they provide for enhancing and maintaining long-term space situational awareness. (shrink)

The main argument in Parmenides’ didactic poem begins with these remarks by the unnamed goddess who delivers the revelation (B2 in Diels-KranzDie Fragmente der Vorsokratiker):Come now and I shall tell you, and you listen to the account and carry it forth, which routes of inquiry (ơδοί…διζησιος, B2.2) alone are for knowing: the one (μέν, B2.3), that (…) is and that it is not possible (for …) not to be ὅπως ἔστιν τε ϰαὶ ὼς οὐϰ ἔστι μὴ είναι, B2.3) is the (...) course of Persuasion, for it attends truth; the other ἠδ; B2.5 that (…) is not and that it is right (for …) not to be (ὡς οὐϰ ἔστιυ τε ϰαὶ ὡς χρεών ἐστι μὴ εἶναι, B2.5) that one I mark for you as being a byway from which no tidings ever come (παναπευθέα ἔμμεν άταρπόυ, B2.6) For you could neither come to know (Υυοίμς, aorist, B2.7) the thing itself which is not (τό Υε μὴ έόυ), for it cannot be consummated (οὐ Υὰρ ἀνυστόυ), nor could you point it out (φράσαις, aorist, B2.8). (shrink)

Analyzes the poem "On Nature" by Parmenides, arguing that is actually a philosophical argument disguised as Homer-like mythological journey. Original.

A natural reading of Hume’s distinction between impressions and ideas is that impressions are forceful perceptions whereas ideas are faint. A problem emerges, however, when Hume countenances the possibility of faint impressions and forceful ideas. In this paper, I attempt a resolution to the problem. I argue that Hume characterizes impressions and ideas intensionally and extensionally, and sometimes uses the term in only one of the two senses. I argue that Hume intensionally defines impressions and ideas as forceful perceptions and (...) weak perceptions, respectively, but takes these to be extensionally equivalent to original and copied perceptions, respectively. Hume recognizes that his two characterizations—the intensional and extensional—don’t perfectly match up, and that there are exceptions to the purported equivalences (the exceptions being disease, sleep, madness, and enthusiasm). Nonetheless, I argue that Hume’s willing to proceed with his definitions. (shrink)

The comment endorses and reinforces Daniel W. Graham’s highly original and attractive proposal that early Greek cosmology develops in two stages. In what Graham calls the “meteorological stage” of the sixth century BCE, celestial objects are explained as formations either from fire or from watery exhalations in a roughly planar model of the cosmos. In the “lithic stage” of the mid- and late fifth century introduced by Anaxagoras, the model is that of a central earth around which solid stone-like celestial (...) objects revolve held aloft in a vortex. The change to the lithic stage comes about, according to Graham, as the implications of Parmenides’ epoch-making discovery that the moon is illuminated by the sun come to be understood and are then theoretically exploited. The present comment also proposes that the false explanations of lunar phases and lunar and solar eclipses in the meteorological-stage cosmologies, respectively, of Xenophanes and of Heraclitus may have played a helpful heuristic role in the theoretical breakthrough to heliophotism. (shrink)

According to the influential Plato-Aristotle account, Parmenides advocates holistic monism (‘all things are one’), and Xenophanes anticipated him by advocating some version of monotheism. Over the last half-century or so, Parmenides studies have disputed this vulgate by arguing that Parmenides’ focus is on the nature of ‘what is’ (to eon), rather than on ‘the One’. Correspondingly, there has developed a tendency to minimize the philosophical importance of Xenophanes, by viewing him primarily as a reformer of Greek religious beliefs and as (...) social critic. I argue that a close study of Xenophanes shows that he had developed a coherent naturalist or physicalist world-view. And this also allows us to gain deeper insights into Parmenides, by viewing the latter as generalizing Xenophanes’ critique of peculiarly ‘anthropist’ (or anthropomorphist) bias in our approach to the universe.Dedication: to Dan Graham. (shrink)

Achieving space domain awareness requires the identification, characterization, and tracking of space objects. Storing and leveraging associated space object data for purposes such as hostile threat assessment, object identification, and collision prediction and avoidance present further challenges. Space objects are characterized according to a variety of parameters including their identifiers, design specifications, components, subsystems, capabilities, vulnerabilities, origins, missions, orbital elements, patterns of life, processes, operational statuses, and associated persons, organizations, or nations. The Space Object Ontology provides a consensus-based realist framework (...) for formulating such characterizations in a computable fashion. Space object data are aligned with classes and relations in the Space Object Ontology and stored in a dynamically updated Resource Description Framework triple store, which can be queried to support space domain awareness and the needs of spacecraft operators. This paper presents the core of the Space Object Ontology, discusses its advantages over other approaches to space object classification, and demonstrates its ability to combine diverse sets of data from multiple sources within an expandable framework. Finally, we show how the ontology provides benefits for enhancing and maintaining longterm space domain awareness. (shrink)

We show how one can obtain solutions to the Arzelà‐Ascoli theorem using suitable applications of the Bolzano‐Weierstraß principle. With this, we can apply the results from and obtain a classification of the strength of instances of the Arzelà‐Ascoli theorem and a variant of it. Let be the statement that each equicontinuous sequence of functions contains a subsequence that converges uniformly with the rate and let be the statement that each such sequence contains a subsequence which converges uniformly but possibly without (...) any rate. We show that is instance‐wise equivalent, over, to the Bolzano‐Weierstraß principle and that is instance‐wise equivalent, over, to, and thus to the strong cohesive principle (). Moreover, we show that over the principles, and are equivalent. (shrink)