This is the second edition of an important introduction to Leibniz's philosophy of logic and language first published in 1972. It takes issue with several traditional interpretations of Leibniz (by Russell amongst others) while revealing how Leibniz's thought is related to issues of great interest in current logical theory. For this new edition, the author has added new chapters on infinitesimals and conditionals as well as taking account of reviews of the first edition.

This is the second edition of an important introduction to Leibniz's philosophy of logic and language first published in 1972. It takes issue with several traditional interpretations of Leibniz while revealing how Leibniz's thought is related to issues of great interest in current logical theory. For this new edition, the author has added new chapters on infinitesimals and conditionals as well as taking account of reviews of the first edition.

Any interesting philosopher’s thoughts contain many prima facie mutually contradicting ideas. Especially if a thinker philosophizes intensely on an extremely wide area of enquiry over a long period, as is the case with Leibniz, advancing many views on each problem, often shifting his position, especially in the context of exchanges of opinions in letters, developing his views without necessarily tying up loose ends, and if in addition the thinker only publishes a minute portion of what he has written, it would (...) be strange, even grotesque, if his writings did not contain conflicting and contradictory strands. What is philosophically interesting, is not so much tracing the exact time of the changes, worthy and difficult as the detective work of historical scholarship involved may be, but realising, through such investigation, the depth and multiple facets of the issue that troubled the philosopher and led him to assert or hold on to those contradictory pairs or groups of ideas. We are sometimes made to realize that the issues throw light on problems that still puzzle us today. (shrink)

Theories of understanding and of language use cannot be detached from theories of truth and reference as many have recently attempted to say. Wittgenstein's early picture theory and his theory of reference {Bedeutung) is part and parcel of his view on understanding meaningful sentences {Sätze), and the use of expressions. His later theory of meaning as use of expressions is inseparable from his view on what kind of objects these expressions refer to. As logical analysis is a quest for definiteness (...) of sense and is not reductionism, not all objects of the Tractatus are of one kind. Singular propositions have no privileged role in linking language to the world. Understanding propositions with proper names or with demonstratives imply understanding of general propositions. This does not entail a definite description view of the sense of proper names. It does suggest that demonstrative pronouns are often not used anaphorically and never purely ostensively. (shrink)

Theories of understanding and of language use cannot be detached from theories of truth and reference as many have recently attempted to say. Wittgenstein's early picture theory and his theory of reference {Bedeutung) is part and parcel of his view on understanding meaningful sentences {Sätze), and the use of expressions. His later theory of meaning as use of expressions is inseparable from his view on what kind of objects these expressions refer to. As logical analysis is a quest for definiteness (...) of sense and is not reductionism, not all objects of the Tractatus are of one kind. Singular propositions have no privileged role in linking language to the world. Understanding propositions with proper names or with demonstratives imply understanding of general propositions. This does not entail a definite description view of the sense of proper names. It does suggest that demonstrative pronouns are often not used anaphorically and never purely ostensively. (shrink)

In order to understand the thoughts of Leibniz it is important to stop putting Leibniz into the convenient pigeon-hole of rationalist, and stop thinking of him merely as the metaphysician and constructor of systems so vividly ridiculed by Voltaire in Candide . Most important of all, one should not attempt to see Leibniz's philosophy as a completely articulated and integrated whole or as built on three or five metaphysical and logical principles. It is better to remember that Leibniz was a (...) very prolific writer, who was interested in the most varied aspects of philosophy, logic, mathematics, natural science, jurisprudence, history and philology: a man who was constantly trying to work out a large number of heterogeneous theories and thoughts. The collected editions of his writings make up more than twenty thick volumes, and these hardly exhaust his manuscripts. Yet this was a man who published only one book in his lifetime. (shrink)

In order to understand the thoughts of Leibniz it is important to stop putting Leibniz into the convenient pigeon-hole of rationalist, and stop thinking of him merely as the metaphysician and constructor of systems so vividly ridiculed by Voltaire in Candide. Most important of all, one should not attempt to see Leibniz's philosophy as a completely articulated and integrated whole or as built on three or five metaphysical and logical principles. It is better to remember that Leibniz was a very (...) prolific writer, who was interested in the most varied aspects of philosophy, logic, mathematics, natural science, jurisprudence, history and philology: a man who was constantly trying to work out a large number of heterogeneous theories and thoughts. The collected editions of his writings make up more than twenty thick volumes, and these hardly exhaust his manuscripts. Yet this was a man who published only one book in his lifetime. (shrink)

Did Leibniz exploit infinitesimals and infinities à la rigueur or only as shorthand for quantified propositions that refer to ordinary Archimedean magnitudes? Hidé Ishiguro defends the latter position, which she reformulates in terms of Russellian logical fictions. Ishiguro does not explain how to reconcile this interpretation with Leibniz’s repeated assertions that infinitesimals violate the Archimedean property (i.e., Euclid’s Elements, V.4). We present textual evidence from Leibniz, as well as historical evidence from the early decades of the calculus, to (...) undermine Ishiguro’s interpretation. Leibniz frequently writes that his infinitesimals are useful fictions, and we agree, but we show that it is best not to understand them as logical fictions; instead, they are better understood as pure fictions. (shrink)

In a seminal essay, Hidé Ishiguro argued that names in the Tractatus are ‘like dummy names’ and that a simple object is to be conceived of as ‘an instantiation of an irreducible predicate’. In this paper, I argue that Ishiguro’s view is incompatible with other claims made in the Tractatus and should be abandoned for this reason. To this end, I adopt a two-step strategy. First, I show that Ishiguro’s view implies the adoption of an anti-haecceitistic position. (...) Then I show that the Tractatus allows for the possibility of there being haecceitistic differences between two complete descriptions of the world. Since anti-haecceitism will be characterized as the doctrine that haecceitistic differences are meaningless, this provides a refutation of Ishiguro’s view. In the final section, I make a few remarks on the relation between anti-haecceitism and the context principle. (shrink)

PrésentationGILLES CAMPAGNOLOL’entretien qui suit ne doit pas induire le lecteur français en erreur : les campagnes continuent d’assurer le maintien au pouvoir quasi continu du PLD depuis sa fondation en 1955 (sauf un très court intermède..

The development of robots that closely resemble human beings can contribute to cognitive research. An android provides an experimental apparatus that has the potential to be controlled more precisely than any human actor. However, preliminary results indicate that only very humanlike devices can elicit the broad range of responses that people typically direct toward each other. Conversely, to build androids capable of emulating human behavior, it is necessary to investigate social activity in detail and to develop models of the cognitive (...) mechanisms that support this activity. Because of the reciprocal relationship between android development and the exploration of social mechanisms, it is necessary to establish the field of android science. Androids could be a key testing ground for social, cognitive, and neuroscientific theories as well as platform for their eventual unification. Nevertheless, subtle flaws in appearance and movement can be more apparent and eerie in very humanlike robots. This uncanny phenomenon may be symptomatic of entities that elicit our model of human other but do not measure up to it. If so, very humanlike robots may provide the best means of pinpointing what kinds of behavior are perceived as human, since deviations from human norms are more obvious in them than in more mechanical-looking robots. In pursuing this line of inquiry, it is essential to identify the mechanisms involved in evaluations of human likeness. One hypothesis is that, by playing on an innate fear of death, an uncanny robot elicits culturally-supported defense responses for coping with death’s inevitability. An experiment, which borrows from methods used in terror management research, was performed to test this hypothesis. [Thomson Reuters Essential Science Indicators: Fast Breaking Paper in Social Sciences, May 2008]. (shrink)