…Marx so far surpasses us all with his genius, his almost excessive scholarly conscientiousness, and his fabulous erudition that if someone were to attempt to criticize his discoveries, he would only get burnt in this endeavor. That will be possible only for people of a more developed epoch.

Le sceptique nous demande " Comment sais-tu que tu as deux mains? Peut-être rêves-tu, ou es-tu trompé par quelque Malin Génie? Peut-on même définir ce que c'est que la connaissance? Va savoir! " Lui rétorquer, comme le faisaient G.E. Moore et la tradition de la philosophie du sens commun : " Mais je sais bien que j'ai deux mains! " semble à la fois une pétition de principe et une bien mauvaise réponse. Le mieux, depuis que nous avons perdu le (...) souci de fonder nos croyance sur des raisons ultimes, serait, tout simplement, de ne pas se soucier des questions du sceptique. Ce que l'on sait dépend, nous dit-on, des circonstances, et toutes nos connaissances sont faillibles. N'y a-t-il pas plutôt des savoirs, dont l'histoire nous montre combien leurs modes de validations sont variés? Ce livre entend refuser ce type de réponse contextualiste et relativiste. Il propose de revenir à la réponse de sens commun de Moore, à partir des reformulations contemporaines des raisonnements sceptiques issues de la philosophie analytique de la connaissance. Personne ne peut nous envoyer savoir quelque chose que nous ne pourrions pas savoir. De fait, nous savons, mais notre savoir n'est pas transparent : nous n'avons pas besoin de savoir que nous savons. Pour parvenir à cette réponse, il faut replacer la notion de connaissance, plutôt que celle de croyance justifiée ou rationnelle, au centre de l'épistémologie, et reformuler des questions traditionnelles comme celles de la nature de la perception, du témoignage, et de la connaissance a priori. On peut aussi reprendre le vieux projet d'une enquête sur la nature de la connaissance en général. (shrink)

The relevance of exchange effects for the stability of superheavy nuclei is examined within a linear QHD-II model by comparing Hartree-Fock with meanfield results. To allow a scan of the complete superheavy regime the recently developed local density approximation (LDA) for the exchange potential is employed for the Hartree-Fock level calculations. It turns out that, while many nuclear properties obtained with the LDA approach differ significantly from the corresponding mean-field results, the predictions of the two methods for shell closures are (...) very similar. Furthermore, a comparison with a nonlinear variant of QHD-II shows that many nuclear properties obtained with the LDA in the framework of linear QHD-II are somewhere in-between the corresponding linear and nonlinear mean-field results. This indicates that the LDA exchange partially includes nonlinear contributions, which supports the interpretation of the meson self-coupling as a parametrization of many-body effects. (shrink)

Combinatory logic started as a programme in the foundation of mathematics and in an historical context at a time when such endeavours attracted the most gifted among the mathematicians. This small volume arose under quite differ ent circumstances, namely within the context of reworking the mathematical foundations of computer science. I have been very lucky in finding gifted students who agreed to work with me and chose, for their Ph. D. theses, subjects that arose from my own attempts 1 to (...) create a coherent mathematical view of these foundations. The result of this collaborative work is presented here in the hope that it does justice to the individual contributor and that the reader has a chance of judging the work as a whole. E. Engeler ETH Zurich, April 1994 lCollected in Chapter III, An Algebraization of Algorithmics, in Algorithmic Properties of Structures, Selected Papers of Erwin Engeler, World Scientific PubJ. Co. , Singapore, 1993, pp. 183-257. I Historical and Philosophical Background Erwin Engeler In the fall of 1928 a young American turned up at the Mathematical Institute of Gottingen, a mecca of mathematicians at the time; he was a young man with a dream and his name was H. B. Curry. He felt that he had the tools in hand with which to solve the problem of foundations of mathematics mice and for all. His was an approach that came to be called "formalist" and embodied that later became known as Combinatory Logic. (shrink)

BackgroundFreezing of gait is a disabling burden for Parkinson’s disease patients with poor response to conventional therapies. Combined deep brain stimulation of the subthalamic nucleus and substantia nigra moved into focus as a potential therapeutic option to treat the parkinsonian gait disorder and refractory FoG. The mechanisms of action of DBS within the cortical-subcortical-basal ganglia network on gait, particularly at the cortical level, remain unclear.MethodsTwelve patients with idiopathic PD and chronically-implanted DBS electrodes were assessed on their regular dopaminergic medication in (...) a standardized stepping in place paradigm. Patients executed the task with DBS switched off, conventional STN DBS and combined STN+SN DBS and were compared to healthy matched controls. Simultaneous high-density EEG and kinematic measurements were recorded during resting-state, effective stepping, and freezing episodes.ResultsClinically, STN+SN DBS was superior to conventional STN DBS in improving temporal stepping variability of the more affected leg. During resting-state and effective stepping, the cortical activity of PD patients in STIM OFF was characterized by excessive over-synchronization in the theta, alpha, and high-beta band compared to healthy controls. Both active DBS settings similarly decreased resting-state alpha power and reduced pathologically enhanced high-beta activity during resting-state and effective stepping compared to STIM OFF. Freezing episodes during STN DBS and STN+SN DBS showed spectrally and spatially distinct cortical activity patterns when compared to effective stepping. During STN DBS, FoG was associated with an increase in cortical alpha and low-beta activity over central cortical areas, while with STN+SN DBS, an increase in high-beta was prominent over more frontal areas.ConclusionsSTN+SN DBS improved temporal aspects of parkinsonian gait impairment compared to conventional STN DBS and differentially affected cortical oscillatory patterns during regular locomotion and freezing suggesting a potential modulatory effect on dysfunctional cortical-subcortical communication in PD. (shrink)

Paul Churchland characterizes the "epistemological problem" in philosophy of mind as the problem "concerned with how we come to have knowledge of the internal activities of conscious, intelligent minds." This problem is itself divided into two separate, but related problems: (1) the problem of self-consciousness -- that of determining how one comes to have knowledge of one's own mental states, and (2) the problem of other minds -- that of explaining how one can ever come to know that something other (...) than oneself has a mind, i.e., is a thinking, feeling, conscious being. My primary aim is to examine and solve the problem of other minds. However, since Churchland contends that the problem of other minds is inextricably intertwined with the problem of self-consciousness, I examine this latter problem, as well. (shrink)

Tels leurs lointains prédécesseurs des Entretiens sur la pluralité des mondes, la Marquise d’U*** et le chevalier d’E*** sont réunis à la campagne et se livrent à des entretiens sur les sciences et la philosophie naturelle. Ils passent en revue les principaux problèmes de la philosophie des sciences, la nature de la découverte, des faits, de la probabilité, le réalisme et l’instrumentalisme, fictions et expériences de pensée, abordent quelques grands sujets de la science d’aujourd’hui, astronomie, chaos et hasard, objets quantiques, (...) nature des entités mathématiques et s’intéressent particulièrement à la biologie évolutionniste et à l’éthologie. Ils débattent des valeurs et des idéaux du savant et de la relation entre la science et la religion. La philosophie, de nos jours, aspire à être populaire, et même "peuple". On fustige son ésotérisme et sa sophistication et l’on voudrait qu’elle soit toujours accessible. Mais ne faut-il pas également songer à l’éducation philosophique des marquises? N’ont-elles pas droit elles-aussi à des introductions claires et légères aux questions centrales de l’épistémologie? Et ce qui est bon pour elles ne peut-il l’être pour tout un chacun? (shrink)

When it comes to second-order knowledge (i.e. knowing that one knows), internalists typically contend that when we know that p, we can, by reflecting, directly know that we are knowing it. Gettier considerations are employed to challenge this internalistic contention and to make out a prima facie case for internalistic metaepistemological skepticism, the thesis that no one ever intemalistically knows that one internalistically knows that p. In particular, I argue that at the metaepistemological second-order level, the Gettier problem generates three (...) distinct problems which, taken together, seriously undermine the possibility of anyone possessing second-order internalistic knowledge. (shrink)

Since ancient times philosophy has dealt with the relation between technology and man. Nowadays this is especially true in the context of the philosophy of technology. Technology is interpreted as an anthropological constant to construct an environment in which man can survive. Acting in the field of technology is to act rationally with a purpose, i.e., in the framework of a means-end relation, and it is employed for coping with experiences (Widerfahrnisse) by means of using tools. Like technology, language can (...) be reconstructed as a symbolic form and thus as a technological means, as a tool so that the employment of metaphors can also be described as an employment of tools. Using technology has effects on man as well as on his self-image. Thus, philosophy of technology creates different ideas of man, which have to become subject to ethical discourses. (shrink)

A filosofia da mente contemporânea, como grande parte da ciência cognitiva, favorece concepções austeras da mente, que buscam explicar a natureza do fenômeno mental a partir de um pequeno conjunto de princípios básicos. Psicologia associacionista, behaviorismo, teorias computacionais e teorias conexionistas da mente são visões deste tipo. Contra elas, argumento que não só a complexidade do fenômeno mental é tal que nenhuma teoria geral deste tipo pode ser possível, mas também que para cada tipo de fenômeno mental um tipo específico (...) de teoria pode ser necessário. Advogo uma concepção da mente como formada por camadas, composta por um número de níveis distintos , cada uma tendo seus princípios específicos e tipo de complexidade. Esse modelo é ilustrado na noção de crença, que compreende vários níveis de complexidade e uma hierarquia estrutural. Concepções dualistas da cognição superior servem como base para este modelo multi-nível. (shrink)