Partial combinatory algebras (pcas) are algebraic structures that serve as generalized models of computation. In this article, we study embeddings of pcas. In particular, we systematize the embeddings between relativizations of Kleene’s models, of van Oosten’s sequential computation model, and of Scott’s graph model, showing that an embedding between two relativized models exists if and only if there exists a particular reduction between the oracles. We obtain a similar result for the lambda calculus, showing in particular that it cannot be (...) embedded in Kleene’s first model. (shrink)

The neuroanatomical substrates controlling and regulating sleeping and waking, and thus consciousness, are located in the brain stem. Most crucial for bringing the brain into a state conducive for consciousness and information processing is the mesencephalic part of the brain stem. This part controls the state of waking, which is generally associated with a high degree of consciousness. Wakefulness is accompanied by a low-amplitude, high-frequency electroencephalogram, due to the fact that thalamocortical neurons fire in a state of tonic depolarization. Information (...) can easily pass the low-level threshold of these neurons, leading to a high transfer ratio. The complexity of the electroencephalogram during conscious waking is high, as expressed in a high correlation dimension. Accordingly, the level of information processing is high. Spindles, and alpha waves in humans, mark the transition from wakefulness to sleep. These phenomena are related to drowsiness, associated with a reduction in consciousness. Drowsiness occurs when cells undergo moderate hyperpolarizations. Increased inhibitions result in a reduction of afferent information, with a lowered transfer ratio. Information processing subsides, which is also expressed in a diminished correlation dimension. Consciousness is further decreased at the onset of slow wave sleep. This sleep is controlled by the medullar reticular formation and is characterized by a high-voltage, low-frequency electroencephalogram. Slow wave sleep becomes manifest when neurons undergo a further hyperpolarization. Inhibitory activities are so strong that the transfer ratio further drops, as does the correlation dimension. Thus, sensory information is largely blocked and information processing is on a low level. Finally, rapid eye movement sleep is regulated by the pontine reticular formation and is associated with a ''wake-like'' electroencephalographic pattern. Just as during wakefulness, this is the expression of a depolarization of thalamocortical neurons. The transfer ratio of rapid eye movement sleep has not yet been determined, but seems to vary. Evidence exists that this type of sleep, associated with dreaming, with some kind of perception and consciousness, is involved in processing of ''internal'' information. In line with this, rapid eye movement sleep has higher correlation dimensions than slow-wave sleep and sometimes even higher than wakefulness. It is assumed that the ''near-the-threshold'' depolarized state of neurons in the thalamus and cerebral cortex is a necessary condition for perceptual processes and consciousness, such as occurs during waking and in an altered form during rapid eye movement sleep. (shrink)

Merker suggests that the thalamocortical system is not an essential system for consciousness, but, instead, that the midbrain reticular system is responsible for consciousness. Indeed, the latter is a crucial system for consciousness, when consciousness is regarded as the waking state. However, when consciousness is regarded as phenomenal consciousness, for which experience and perception are essential elements, the thalamocortical system seems to be indispensable. (Published Online May 1 2007).

At the heart of Karl Jaspers on Truth and Dialogue is the question of the possibilities and limits of global communication. Anton Hügli shows how disastrous it is for the individual, for society, and for the destiny of humanity when the will to communicate is lacking.

In this pa per I will try to of fer a syn the sis be tween two con flict ing epistemological po si - tions on the re cent philo soph i cal scene: pos i tiv - ism, whose her i tage sur vives as the be lief that sci ence is the most gen u ine form of knowl edge, and the de fend ers of incommensur..

Papers originally presented at a symposium in Bad Homburg, Germany, in April 1993.

This article seeks to interpret how the scientific study of individualization, broadly construed, is conceived from within. It presents and discusses an analysis of qualitative data gained from performing semi-structured expert interviews. By way of a thematic-analytic approach to interpreting this data, this article seeks to investigate the attitudes and opinions of a sample of scientific experts who study individualization, across a wide range of scientific fields, with regard to key concepts, phenomena, motivating factors, and open questions. Centering its analysis (...) on discussion of four themes, this paper (1) emphasizes the importance for science of individuals and individuality, (2) reflects on matters pertaining to language and interdisciplinary communication, (3) distinguishes between nine meanings of the word “individualization,” stressing their significant features, and (4) considers ideas about the consequences of individualization and ongoing methodological concerns. (shrink)

Marxism -- Middle-class materialism -- Dietzgen -- Mach -- Avenarius -- Lenin -- The Russian revolution -- The proletarian revolution.

The aim of the present paper is to situate the recent attempts devoted to the study of the phenomena of knowledge management in a larger epistemological context. More precisely, I intend to ascertain the entire affair from the perspective of the philosophy of the humanities. This involves understanding it as an endeavor concerned with the search for regularities. As a result, key notions figuring in the repertoire of this kind of undertaking, primarily those of notes and notebooks, are scrutinized for (...) the purpose of revealing their theoretical function. This points towards some ontological issues, such as the idea of taking notes as cultural kinds, namely something analogous to the idea of natural kinds. (shrink)

The validity of dream recall is discussed. What is the relation between the actual dream and its later reflection? Nielsen proposes differential sleep mentation, which is probably determined by dream accessibility. Solms argues that REM sleep and dreaming are double dissociable states. Dreaming occurs outside REM sleep when cerebral activation is high enough. That various active sleep states correlate with vivid dream reports implies that REM sleep and dreaming are single dissociable states. Vertes & Eastman reject that REM sleep is (...) involved in memory consolidation. Considerable evidence for this was obtained by REM deprivation studies with the dubious water tank technique. [Nielsen; Solms; Vertes & Eastman]. (shrink)

Walker's target article proposes a refinement of the well known two-stage model of memory formation to explain the positive effects of sleep on consolidation. After a first stage in which a labile memory representation is formed, a further stabilisation of the memory trace takes place in the second stage, which is dependent on (REM) sleep. Walker has refined the latter stage into a stage in which a consolidation-based enhancement occurs. It is not completely clear what consolidation-based enhancement implies and how (...) it can be dissociated from a stage for memory-stabilisation. A more serious consideration, however, is whether a second stage in memory consolidation that is solely dependent on sleep, is really necessary. The classical, passive, interference theory is able to explain adequately the findings related to the effects of sleep and memory, and can lead perhaps better to an understanding of the highly variable data in this field. (shrink)

The aim of the present paper is to provide a comparative account of the manner in which Moritz Schlick and Wilfrid Sellars treat certain aspects surrounding the topic of observational knowledge. By considering Sellars’s allusions to Schlick’s epistemological undertaking within the context of his rejection of givenness, I evaluate the extent to which Schlick can be characterized as a traditional foundationalist. By emphasizing that this is not the case and that Schlick adheres to a non-standard version of epistemological foundationalism, I (...) shed some light on those theoretical elements that allow for a convergence of opinions between the two authors to transpire. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Notes and Discussions ARISTOTLE'S ALLEGED "REVOLT" AGAINST PLATO Hermippus' most conspicuous contribution to Aristotle's biography probably was his determined effort to depict Aristotle as the founder of an original school of philosophy which was wholly independent of Plato and Platonic teachings. Among the several and, in all likelihood, fanciful stories about Aristotle he invented or propagated, the most startling was the account, subsequently widely accepted (and widely exploited by (...) the detractors of Aristotle), that after having been a disciple of Plato for a while, he seceded from the Academy and from Plato's philosophic teachings while Plato was still alive. 1 Accordingly, he owed little to Plato and to the Academy. This story, invented and propagated by an inveterate Peripatetic (Hermippus), was intended to demonstrate the original philosophic genius of Aristotle which developed in complete independence of Plato and necessitated a break with the master's teachings. In devising his argument, Hermippus might have made use of a report, found in some of Aristotle's ancient biographers, that a few brash young men (members of the Academy?) revolted against Plato and, in a spirit of independence, defiance and antagonism, attempted to start a school of their own which would rival the intellectual standing of the Academy. 2 Hermippus, it appears, subsequently identified these young "rebels" with Aristotle, a substitution convenient to Hermippus" aim to depict Aristotle as a wholly independent and totally original philosopher who owed nothing whatever to Plato and his teachings. In all likelihood, Diogenes Laertius' statement that Aristotle "seceded from the Academy while Plato was still alive," a is just an echo either of a statement made by Hermippus himself or is a conclusion drawn from the several unpleasant stories about Aristotle invented and reported by some of Aristotle's detractors. According to these derogatory stories, there existed many serious personal as well as doctrinal 4 disagreements or rifts between Plato and the Stagirite--disagreeDiogenes Laertius, V. 2. See also Eusebius, Praeparatio Evangelica, XV. 2. 3, and ibid., XV. 2. 13 (Aristoxenus); Aelian, Varia Historia, IV. 9; Theodoretus, Graecorum Affectionum Curatio, IV. 46; St. Augustine, De Civitate Dei, VIII. 12; Philoponus, Comment. in Aristotelis Analytica Posteriora, CIAG, vol. XIII, part 3, pp. 133, 30 ft. 2 See Aelius Aristides, Oratio XLVI, 249. 10. See also note 1, supra. s Diogenes Laertius, V. 2. See also Vita Aristotelis Marciana 9; Vita Aristotelis Latina 9. 9 See, for instance, Plutarch, Adversus Coloten 14 (Moralia, III5A); Cicero, Academica I. 9. 33; Eusebius, op. cir., XV. 2, passim; Diogenes Laertius III. 37; Justin Martyr, Cohortatio ad Graecos 5 (Migne, PG. vol. VI. p. 247); Cyrillus, Contra Julianum II. 47; Proclus, [91] 92 HISTORY OF PHILOSOPHY ments whichmarred the relations between these two men and which were indicative of Aristotle's ingratitude, bad taste and unwarranted conceit. The report of Diogenes Laertius, in an oblique manner, may also refer to the fact that already during his active association with the Platonic Academy (367-348 B.c.), that is, in his On (the) Ideas and On the Good, Aristotle had begun to disagree with, and criticize, some of Plato's fundamental teachings. It may also, in a distorted form, refer to the following specific incident which, however, cannot be verified: According to Aristoxenus, during the absence of Plato in Syracuse (and while Heracleides of Pontus was the "acting scholarch" of the Academy),5 some unnamed young members of the Academy, or "students" or, perhaps, some "outsiders " attempted to start a rival school (within the Academy?).6 As a matter of fact, Aelian, who apparently dramatizes this incident, reports that during Plato's last years, that is, some time after Plato's return from his third and last voyage to Syracuse, a serious conflict or confrontation arose within the Academy. Aristotle, together with some of his friends, or "conspirators," we are told, harrassed and molested the aging Plato by constantly putting questions to him, by arguing with him in an insolent manner, by contradicting him on every point, and by attempting to involve him in hair-splitting dialectics. At the time Xenocrates was in Chalcedon, and Speusippus was gravely ill. Hence, neither of them could come to the succor of Plato. In... (shrink)