tic sequenzen-kalkul of Gentzen, into rules for PCc, the classical sequenzenkalkul. We shall limit ourselves here to sequenzen or turnstile statements of the form A„A„..., A„ I- B, where A„A„..., A„(n ~ 0), and B are wffs consisting of propositional variables, zero or more of the connectives '5', "v', ' ', ')', and '=', and zero or more parentheses. One can pass from PCi to PCc by amending the intelim rules for ' a result of long standing, or by amending (...) the intelim rules for either one of.. (shrink)

The essays in philosophical logic collected in this volume are dedicated to Henry S. Leonard who was one of the first American philosophers to urge the application of modern logic to non-mathematical areas. Leonard also inspired the development of certain areas of contemporary philosophical logic discussed in some of the papers of this volume. This is especially clear in the case of free, or presupposition free, logics which Leonard's early work on a logic of existence inspired. In one essay of (...) this volume Bas C. Van Frassen further develops his work on the semantics of free logic. In another, Milton Fisk relates free logic to modal logic, suggesting a new semantics of strength to deal with various problems in the area and in a third essay, Karel Lambert relates free logic to certain logical puzzles about quantum theory. Leonard was also one of the first to entertain the idea of and discuss a logic of questions and an erotetic logic or logic of interests. The volume contains essays on these topics by Nuel D. Belnap and David Harrah. Leonard's interest in modal logic is reflected in Fisk's article as well as in an article by Richmond Thomason on modal logic and metaphysics. His interest in epistemic logic is seen in an essay on the logic of belief by Jon Vickers and an essay by Hintikka applying the logic of belief and knowledge to problems about the ontological argument. In addition to these essays, there are five others of high quality on diverse topics: R. M. Martin on intentions, Wilfrid Sellars on the metaphysics of the person, R. M. Chisholm on agency, Frederick Fitch on combinatory logic and negative numbers, and H. E. Hendry and G. J. Massey on Sheffer functions. This is a worthy memorial to a quietly influential American philosopher.--R. H. K. (shrink)

This article sheds new light on late-19th-century debates about the organization of knowledge through its emphasis on German orientalism and comparative linguistics. Centering on Friedrich Carl Andreas’ (1846–1930) controversial reconstruction of the Avestan language and its sacred literary corpus, I highlight a shift from the history of texts to an engagement with ‘living’ language in the decades around 1900. Andreas is shown to have inherited aspects of two schools, which collectively defined the landscape of 19th-century philological research – one traditional (...) and the other comparative. The long-standing struggle between these schools demonstrates that ‘the humanities’ were no monolithic foil to the rise of natural sciences during the second half of the 19thcentury. Instead, I argue that alternative conceptual frameworks were cultivated within German philology – concepts that were taken up in broader disciplinary debates, though they were not narrowly the products of them. (shrink)

The existence of consciousness in animals may have been overlooked. Continuity in consciousness between humans and animals is predicted by evolutionary theory. However, there are specific methodological difficulties associated with investigating such a phenomenon: it cannot be directly measured; animals, unlike humans, cannot directly tell us about their conscious experience; experiments which have made comparisons to human consciousness cannot detect consciousness of a different form; application of the law of parsimony in science has traditionally led to the conclusion that it (...) does not exist. (shrink)

Beginning with an overview of Galileo's earliest work on free fall, the paper examines the relationship between experiment and theory in his study of motion in the period immediately before and after 1604. The possible role of experiment is assessed in relation to the manuscript evidence and by means of reconstructed experiments.

The time taken to react voluntarily to a stimulus is far longer than can be accounted for by ordinary processes of nerve conduction and synaptic delay, and varies unpredictably from trial to trial. Though random, the distribution of reaction times usually follows a relatively simple law, which in turn can be explained by the LATER model, in which a decision signal, representing belief in the existence of the target, rises in response to incoming sensory evidence from an initial value to (...) a criterion level at which action is initiated. But the rate of rise fluctuates randomly from trial, to an extent that cannot be explained by sensory noise at the input. These conclusions, confirmed by recording from neurons in the frontal eye fields, suggest that the randomness of reaction time is due to a deliberate, gratuitous, neural process which confers certain biological advantages as well as having implications for general ideas about the nature of ‘free will'. (shrink)

Bernard Nieuwentijt ist in der Mathematikgeschichte bekannt als Kritiker der Leibnizschen Differentialrechnung. Im Gegensatz zu dem, was häufig angenommen wird, war die Kritik an Leibniz' Methode kein Hauptanliegen Nieuwentijts. Das Ziel seines bedeutendsten mathematischen Werks, Analysis infinitorum , war die Systematisierung und logische Deduzierung der ihm bekannten Infinitesimalmethoden, besonders derer von den Engländern wie Barrow, Wallis u. a. Das Werk Leibnizens war ihm anfangs völlig unbekannt. In dem System, das Nieuwentijt selbständig entwarf, rechnete er nicht mit Infinitesimalen höheren Grades: ihre (...) Existenz hielt er für unmöglich. Dies brachte ihn zur Kritik der Leibnizschen Methode, als er später auf dessen Werk stieß. Später aber erkannte er die Unhaltbarkeit seiner Kritik, wie klar wird aus seinem posthumen Werk Gronden van zekerheid . Der Aufsatz gibt überdies zur Fundierung dieser Thesen einen sehr kurzen Überblick über Nieuwentijts mathematische Arbeiten und eine Besprechung neuerer Interpretationen. (shrink)

Summary One aim of this paper is to provide an assessment of the recent attempts to interpret the development of Galileo's theory of motion in the late Paduan period 1604?1610. In addition to this a new interpretation of this process of development is advanced. This interpretation is the first that proves able to provide a full account of all the features on folio 152r of volume 72 of the Galilean manuscripts which has been claimed to be of crucial significance. The (...) major feature of the interpretation is that it is the first to account for the relationship between Galileo's theoretical and experimental work in the period 1604?1610. (shrink)

Recent study of Galileo's surviving manuscript notes on motion has revealed that by 1609 he had developed the major part of his theory of projectile motion. During the period of these theoretical advances Galileo was engaged in important related experimental investigations; this has become clear from the study of folios 114r and 116v of the manuscript on motion. This paper provides an interpretation of a manuscript not previously discussed—folio 81r. The analysis provided indicates that it is evidence of an important (...) early experiment of the series in which Galileo studied the projectile trajectory. The reconstruction of the experiment concerned reveals relationships with the enquiries suggested by folio 114r and 116v and indicates that Galileo examined the form of projectile trajectories with some care. (shrink)

Plato was born around 2,500 years ago. He lived in a small city-state in Greece and busied himself with the problems of his fellow Greeks, a people living in scattered cities around the Mediterranean and the Black Sea. In all he tried to do for the Greeks he failed. Why, then, should people in the modern world bother to read what he had to say? Does it make sense to go to a Greek thinker for advice on the problems of (...) an age so different from his own? To anyone who has questioned the relevance of Plato to the modern world Richard Crossman’s lively book provides a brilliant reply. The problems facing Plato’s world bear striking parallels to ours today, the author maintains, so who better to turn to than Plato, the most objective and most ruthless observer of the failures of Greek society. Crossman’s engaging text provides both an informed introduction to Greek ideas and an original and controversial view of Plato himself. (shrink)

The essays in this volume are based on addresses given during a colloquium on free logic, modal logic, and related areas held at the University of California in 1968. The majority of the contributors are well known for their writings in these fields and their papers are as illuminating as they are technical. In the first paper, Lambert and Bas C. Van Fraassen apply free logic to several controversies in quantified modal logic. One of these is Putman's argument that 'Nothing (...) is both red and green all over' can be had as a theorem of modal logic. Lambert and Van Fraassen provide a counter example to this claim and then show that the argument only holds in systems allowing possible individuals. Jaako Hintikka's essay also deals with 'free' modal logics in much the same way as Hintikka's other papers and discusses some of the criticisms of Quine of the entire enterprise of quantified modal logic. In another paper, H. Leblanc and R. K. Meyer provide truth-value semantics for the theory of types and hence an alternative semantic structure for functional calculi of any order. In addition to these essays, there are papers by R. Thomason and Dana Scott on modal logic, J. Vickers on probability logic, and Peter Woodruff on truth value gaps. To anyone interested in these various areas this collection is sure to be welcome.--R. P. M. (shrink)