Logical frameworks for analysing the dynamics ofinformation processing abound [4, 5, 8, 10, 12, 14, 20, 22]. Some of these frameworks focus on the dynamics of the interpretation process, some on the dynamics of the process of drawing inferences, and some do both of these. Formalisms galore, so it is felt that some conceptual streamlining would pay off. This paper is part of a larger scale enterprise to pursue the obvious parallel between information processing and imperative programming. We demonstrate that (...) logical tools from theoretical computer science are relevant for the logic of information flow. More specifically, we show that the perspective of bare logic [13, 18] can fruitfully be applied to the conceptual simplification of information flow logics. Part one of this program consisted of the analysis of 'dynamic interpretation' in this way, using the example of dynamic predicate logic ; the results were published in . The present paper constitutes the second part of the program, the analysis of 'dynamic inference'. Here we focus on Veltman’s update logic . Update logic is an example of a logical framework which takes the dynamics of drawing inferences into account by modelling information growth as discarding of possibilities. This paper shows how information logics like update logic can fruitfully be studied by linking their dynamic principles to static 'correctness descriptions'. Our theme is exemplified by providing a sound and complete HoarelPratt style deduction system for update logic. The Hoare/Pratt correctness statements use modal propositional dynamic logic as assertion language and connect update logic to the modal propositional logic S5. The connection with S5 provides a clear link between the dynamic and the static semantics of update logic. The fact that update logic is decidable was noted already in ; the connection with S5 provides an alternative proof. The S5 connection can also be used for rephrasing the validity notions of update logic and for performing consistency checks. In conclusion, it is argued that interpreting the dynamic statements of information logics as dynamic modal operators has much wider applicability. In fact, the method can be used to axiomatize quite a wide range of information logics. (shrink)
In this paper we present a dynamic assignment language which extends the dynamic predicate logic of Groenendijk and Stokhof [1991: 39–100] with assignment and with generalized quantifiers. The use of this dynamic assignment language for natural language analysis, along the lines of o.c. and [Barwise, 1987: 1–29], is demonstrated by examples. We show that our representation language permits us to treat a wide variety of donkey sentences: conditionals with a donkey pronoun in their consequent and quantified sentences with donkey pronouns (...) anywhere in the scope of the quantifier. It is also demonstrated that our account does not suffer from the so-called proportion problem.Discussions about the correctness or incorrectness of proposals for dynamic interpretation of language have been hampered in the past by the difficulty of seeing through the ramifications of the dynamic semantic clauses (phrased in terms of input-output behaviour) in non-trivial cases. To remedy this, we supplement the dynamic semantics of our representation language with an axiom system in the style of Hoare. While the representation languages of barwise and Groenendijk and Stokhof were not axiomatized, the rules we propose form a deduction system for the dynamic assignment language which is proved correct and complete with respect to the semantics. (shrink)
The Dutch philosopher of religion Hent de Vries has explored and complicated the boundaries between religion and modern thought in order to create the space for an innovative “minimal theology.” This article reconstructs de Vries's interpretation of the changes in Theodor W. Adorno's thought between Dialectic of Enlightenment and Negative Dialectics in order to demonstrate its fecundity for a philosophical account of otherness. It also examines and defends de Vries's own rhetorical mode of reading texts as an (...) exemplary approach to philosophical dialogue. Finally, however, the essay challenges de Vries's privileging of the religious as the site of ethical relationality and his intentional bracketing of Adorno's critical social theory. (shrink)
De Vries' mutation theory has not stood the test of time. The supposed mutations of Oenothera were in reality complex recombination phenomena, ultimately explicable in Mendelian terms, while instances of large-scale mutations were found wanting in other species. By 1915 the mutation theory had begun to lose its grip on the biological community; by de Vries' death in 1935 it was almost completely abandoned. Yet, as we have seen, during the first decade of the present century it achieved (...) an enormous popularity. As this paper has tried to suggest, one of the principal reasons for this was that de Vries' theory served as a banner around which a whole crowd of disaffected Darwinians or anti-Darwinians could rally. However, not all of those who favored de Vries did so for quite the same reasons. Underlying the multitude of views ran several common threads: a dissatisfaction with current Darwinian theory born out of misunderstanding natural selection, a general misunderstanding of the nature of species, and a prejudice against speculative, nontestable theories in biology.Supporters of de Vries were not the only opponents of Darwinism, nor was the mutation theory the only alternative to natural selection. In the early twentieth century a number of theories had been proposed to explain away the problems which Darwin had left unsolved. There was the idea of orthogenesis, championed by the American paleontologists Cope, Osborn and others; organic selection (or orthoplasy) was championed by M. M. Baldwin and C. Lloyd Morgan; there were the concepts of convergent evolution proposed by Hermann Friedmann, the theory of physiological selection by John George Romanes, and the concepts of reproductive divergence by H. M. Vernon. Virtually none of these men either accepted or were strong supporters of the de Vriesian theory, for each had his own particular ‘ism” to advocate as the major factor in evolution. The existence of a large number of such theories, each purporting to be the explanation, was characteristic of evolutionary theory at the turn of the century. It is to a large extent the emphasis on such fragmentary concepts that retarded development of the comprehensive theory of evolution which emerged in the 1920's and 1930's. For the historian, however, a study of these alternative theories is instructive in trying to understand the inherent difficulties which Dawwinian theory posed to biologists at the time. De Vries' mutation theory serves historically as a mirror to reflect the critical mood of a generation hostile to the theory of natural selection.It has often been claimed that it was impossible to understand the mechanism of natural selection until it could be placed in genetic and mathematical terms. It is certainly true that great strides have been made in population genetics and the treatment of evolutionary concepts with mathematical tools in the last forty years. But the very people who developed the genetical and mathematical approach to evolution were already convinced of the essential correctness of Darwinian theory before they started. Advances in an understanding of Mendelian heredity aided greatly in solving one important issue for evolutionists: the origin of variations. And the rigor with which selection acted could best be studied by observing changes in gene frequencies (calculated mathematically) over a number of generations. But as this paper has shown, two of the basic problems which biologists faced in evaluating Darwinian theory at the turn of the century-the nature of species, and the criteria of what constituted an acceptable explanation in biological science-could not be answered directly by mathematics. What mathematical and genetical theory did do was to help convince the skeptics of the validity of the Darwinian proposition.The change in explanatory criteria which many hailed as de Vries' most important contribution to evolutionary theory seems to have been part of a general emergence of twentieth-century biology from the domination of theorizers in the nineteenth. It also marked the emergence of America from the domination of biological, and particularly evolutionary, influence of Europeans. The change occurred in three areas: in the kinds of questions asked: testable versus non-testable; in the kind of data sought: quantitative versus qualitative; and in the kinds of theories proposed: analytical and reductive—the attempt to see complex processes in terms of simpler components-as opposed to synthetic and speculative. Although ultimately wrong in his idea, de Vries and his theories rode high on the wave of “experimentalism” which was the harbinger of a new era in evolutionary theory. (shrink)
Traveling-wave solutions of the standard and compound form of Korteweg–de Vries–Burgers equations are found using factorizations of the corresponding reduced ordinary differential equations. The procedure leads to solutions of Bernoulli equations of non-linearity 3/2 and 2 (Riccati), respectively. Introducing the initial conditions through an imaginary phase in the traveling coordinate, we obtain all the solutions previously reported, some of them being corrected here, and showing, at the same time, the presence of interesting details of these solitary waves that have (...) been overlooked before this investigation. (shrink)
Summary This note discusses lecture plates at the Hugo de Vries Laboratorium that may be relevant to Hugo de Vries's claim to have independently discovered Mendel's law of segregation. Dating when the plates were made is problematic.
Summary It is argued that Hugo de Vries's conversion to Mendelism did not agree with his previous theoretical framework. De Vries regarded the number of offspring expressing a certain character as a hereditary quality, intrinsic to the state of the pangene involved. His was a shortlived conversion since after the ?rediscovery? he failed to unify his older views with Mendelism. De Vries was never very much of a Mendelian. The usual stories of the Dutch ?rediscovery? need, therefore, (...) a considerable reshaping. (shrink)
This article puts Korteweg and de Vries's manuscript (published in the Philosophical Magazine in 1895) in historical context. The article highlights the importance of the Korteweg?de Vries equation in the development of concepts used in nonlinear physics and also mentions some of their recent applications.
The almost simultaneous and overlapping discoveries of Mendel's forgotten work by Hugo de Vries, Carl Correns, and Erik von Tschermak gave rise to an intense rivalry, some jealousy, and more than a little illfeeling. De Vries, the first to announce the discovery, has been subjected to the charge that he wished to conceal his discovery and to obtain for himself the credit for having discovered what we now call Mendelism. This charge involves the statement that de Vries (...) gave credit to Mendel only after he had found that others had also read Mendel's papers. The evidence on which this charge is based is sketchy, and we can now show that at least that portion of it that is based on supposed alteration in the proof of de Vries' paper in the Berichte is without foundation. Unfortunately, de Vries gave three different accounts of how he was led to Mendel's work. Two of these involve Liberty Hyde Bailey.Bailey had listed Mendel's papers in a bibliography that he published in 1892 in The Rural Library. Bailey did not include this bibliography in the first edition (1895) of Plant Breeding or in its reprinting in 1896 and 1897. He did include the bibliography in the second edition (1902), but this was after de Vries and others had called attention to Mendel. In 1899, both Bailey and de Vries gave papers at the Hybrid Conference held at Chiswick, England, but we have no record of their having discussed Mendel. What evidence we have indicates that, at this time, neither of them had read Mendel's papers.De Vries wrote to Bailey that it was Bailey's listing of Mendel in the bibliography published in The Rural Library that led to his discovery of Mendel. Later, de Vries wrote to H. F. Roberts that he had first found a reference to Mendel in Bailey's Plant Breeding of 1895, where the bibliographic reference to Mendel's papers was not published. Finally, de Vries told Th. J. Stomps, who succeeded him at the University of Amsterdam, that he had first learned of Mendel early in 1900 from a reprint of Mendel's paper sent him by his friend Professor M. W. Beyerinck. Our present evidence favors Stomp's account as it shows that de Vries had not read Mendel's papers in 1899 but had early in 1900.Attempts to pinpoint de Vries' discovery of Mendel are aided in part, and in part confused, by the fact that he published five relevant papers in 1900. These papers were in press simultaneously, and some of them were altered in proof. Further confusion is due to the fact that at least three of them were published in the reverse order of their acceptance for publication. Unfortunately we do not have the crucial dates for all of the papers.J. Roy. Hort. Soc. 24: 69–75. A definitely pre-Mendelian paper given on 11 July 1899, and published in 1900 (possibly in April). The evidence for an alteration in proof after de Vries had read Mendel is shown by the fact that de Vries described a ratio of 99 to 54 as a 3 to 1 ratio.Rev. gén. botan. 12: 129–137. A Mendelian paper, giving the 3 to 1 ratio in the F2 generation of a cross between starchy and sugary corn. The paper is not dated by de Vries but it was published in the volume, 128 pages ahead of a paper de Vries dated 19 March. In a footnote, de Vries cites a paper by Correns that was published on 25 January, so we can tell that it was written or corrected in proof after this date. Here Correns showed de Vries that he had already read Mendel's paper. Any attempt by de Vries to ignore Mendel or get credit for Mendelism after 25 January would have been senseless. This date was nearly two months before de Vries' Berichte paper was submitted for publication.Ber. deut. botan. Ges. 18: 83–90. Accepted for publication 14 march, published 25 April. This paper gives Mendel full credit and stimulated the publications of Correns and von Tschermak. As de Vries was aware that Correns already knew of Mendel when the paper was first submitted, there was no occasion to alter it in proof.Rev. gén. botan. 12: 257–271. Dated by de Vries 19 March, but the proof was read after June. De Vries cites von Tschermak's paper in the Berichte that was published in June. The Revue paper is a Mendelian paper, and Mendel is cited on the last page.C. R. Acad. Sci. (Paris) 130: 845–847. Accepted for publication 26 March 1900. Reprint received by Correns 21 April. Mendel is not mentioned but de Vries' use of terms told Correns that de Vries had read Mendel's paper. First of the papers to be published, it caused Correns to assume that de Vries wanted the credit that was due Mendel.The three discoverers of Mendel did not form a mutual admiration society. (shrink)
El artículo desarrolla una hermenéutica fenomenológica de las relaciones entre historia, sentido, existencia y eternidad en la filosofía de la historia de Jan Pato¹ka. Primero determina las nociones de sentido e historia. Luego explicita en qué medida la existencia humana constituye la condición de posibilidad de un sentido problemático y concurrente de la historia. Finalmente analiza la �existencia en la verdad� como resultado de una correlación entre existencia y eternidad y comprende la interpelación de la eternidad como origen del sentido.
Logical frameworks for analysing the dynamics of information processing abound [4, 5, 8, 10, 12, 14, 20, 22]. Some of these frameworks focus on the dynamics of the interpretation process, some on the dynamics of the process of drawing inferences, and some do both of these. Formalisms galore, so it is felt that some conceptual streamlining would pay off.This paper is part of a larger scale enterprise to pursue the obvious parallel between information processing and imperative programming. We demonstrate that (...) logical tools from theoretical computer science are relevant for the logic of information flow. More specifically, we show that the perspective of Hoare logic [13, 18] can fruitfully be applied to the conceptual simplification of information flow logics. (shrink)
L?intention de cet article est de présenter la critique et le remaniement de l?intentionnalité qu?implique l?élaboration d?une phénoménologie asubjective chez Jan Pato?ka. À cette fin, nous exposerons d?abord les raisons qui amènent Pato?ka à prendre ses distances par rapport au subjectivisme de la phénoménologie husserlienne, et les conséquences de ce dépassement de l?horizon transcendantal de la subjectivité. Et dans un deuxième temps nous tâcherons de suivre les implications de cette destitution du subjectivisme relativement au statut et au sens de l?intentionnalité. (...) La nécessité d?élaborer une phénoménologie asubjective et de proposer par là une alternative au subjectivisme et à l?idéalisme implicite de la phénoménologie husserlienne découle chez Pato?ka d?une volonté de rendre compte plus authentiquement, c'est-à-dire plus phénoménologiquement, de la structure et de la modalité de l?apparaître. En effet, c?est en s?interrogeant sur le comment de l?apparaître que Pato?ka est conduit à affirmer que celui-ci ne peut pas être expliqué à partir d?un sujet qui, avant tout, est lui-même quelque chose d?apparaissant. S?il apparaît à son tour, c?est qu?il est soumis lui-même à la légalité de l?apparaître, au lieu d?en être le principe. À partir de ces considérations, il devient possible de formuler une alternative tranchée entre deux types de phénoménologie, comme le. (shrink)
Le phénoménologue tchèque Jan Pato?ka, auteur d?une phénoménologie asubjective défendant la thèse d?un procès asubjectif de l?apparaître (d?une autonomie du phénomène par rapport à l?ego), a accordé au problème des relations nécessaires et difficiles que la philosophie entretient en son sein même avec la littérature une attention particulière qui l?a conduit à poser les fondements d?une phénoménologie de la littérature centrée autour de l?idée d?un asubjectivisme de l?écrivain. Nous suivrons ici deux axes de réflexion connexes: premièrement, nous montrerons pourquoi et (...) comment Pato?ka restaure le vocabulaire et la vision de l?homme propres au mythe et reprend ce qu?il aperçoit comme le fondement de la tragédie pour élaborer une nouvelle compréhension du phénomène de l?existence comme mouvement. Deuxièmement, nous décrirons le rôle que joue l?écrivain moderne à une époque marquée par la fragmentation de la vie. Car l?écrivain qui édifie une ?littérature métaphysique? a le privilège, selon Pato?ka, d?être ?l?administrateur propre et originel de l?intégralité de la vie et de la totalité universelle?, il est ainsi une sorte de ?quasi-phénoménologue? dont la philosophie ne peut se passer si elle veut saisir ces phénomènes qui, sans être purement et simplement subjectifs, ne peuvent néanmoins être réduits à l?objectivité du concept. (shrink)