PHILOSOPHIA SCIENTIÆ RUDOLPH HALLER Conventionalism and it’s impact on logical empiricism Philosophia Scientiæ, tome 3, no 2 (1998-1999), p. 95-108 <http://www.numdam.org/item?id=PHSC_1998-1999__3_2_95_0> © Éditions Kimé, 1998-1999, tous droits réservés. L’accès aux archives de la revue « Philosophia Scientiæ » (http://poincare.univ-nancy2.fr/PhilosophiaScientiae/) implique l’accord avec les conditions générales d’utilisation (http://www. numdam.org/conditions). Toute utilisation commerciale ou im- pression systématique est constitutive d’une infraction pénale. Toute copie ou impression de ce fichier doit contenir la pré- sente mention de copyright. Article numérisé dans le cadre du programme Numérisation de documents anciens mathématiques http://www.numdam.org/ Conventionalism and it's Impact on Logical Empiricism Rudolph Haller University ofGraz Philosophia Scientiae, 3 (2), 1998-1999, 95-108 96 Rudolph Haller In my paper I want to do three things : first, to give an outline of the phi- losophical scenery into which the conventionalistic approach brought about a new perspective. Then I want to sketch the important thèmes of the Austrian empiricists and the impact of the French philosophers of science on the Viennese philosophers. Finally I shall try to evaluate the interplay between the French and Austrian philosophers and to point out the far-reaching change which it brought about in présent day-philosophy. I am convinced that what we are involved in, namely in an attempt to understand the main line of thought of the conventionalistic thinkers, is not only interesting from a historical point of view, which it surely is, but much more so from a philosophical point of view. If it is really true what I think is true, namely that among those philosophical ideas which had the deepest influence on philosophy in gênerai and especially on philosophy of science in this century, conventionalism and pragmatism were the most fruitful ones. Biased as I am in this regard, I do hope that this confé­ rence will lead to justify this opinion. §i. As Auguste Comte optimistically had foreseen, sociology and psycho- logy were the latest among sciences which freed themselves from their old mother - philosophy. The fast development of the natural sciences in the 19th cen­ tury was one of the reasons why materialistic ideas were flourishing. However, the main attraction were the différent scientists and physicists like John F.W .Herschel, James Clerk Maxwell, Hermann von Helmholtz, and mathema- ticians like Augustin-Louis Cauchy or Cari Friedrich GauB and Richard Dedekind, who are just mentioned hère as examples of a rich and important concentration of the scientific community in the earlier décades of the last cen­ tury. In the later part of it one of the most important révolutions, the „Darwinian Paradigm" (M. Ruse), began to influence also the other sciences and philoso­ phy. The crude materialistic explanations we find for instance in Ludwig Buchner, lost their significance becaus* of the psycho-physics of Fechner and his followers. With thèse ideas the first steps of a scientific physiology were made in a field where also Mach started his early experiments. One has only to read the writings of Ernst Mach and Ludwig Boltzmann to realise the strong Darwinian influence on their gênerai view of nature and of théories. In the mainstream of this development we see also Franz Brentano, who even during his priesthood tried to présent Comte as an important philosopher to the German Catholic audience. Few years later, when starting his career in Austria, he published the famous Psychology from an Empirical Point ofView, a work announced as comprising six volumes, of which only the first one in 1874 was published according to the original plan. With this book started what Brentano had called the project of «descriptive psychology" or „beschreibende Phànomenologie". Descriptive psychology - contrary to genetic psychology which aims to explain the causes of the psychological phenomena - was thought Conventionalism and it's Impact on Logical Empiricism 97 to describe the phenomena of the human consciousness, the éléments of our psychological life. Its task therefore is, first of ail, to provide a clear criterion to distinguish the psychological from the physical phenomena. As phenomena count only what can be object of our inner perception, that is objects like our thinking, our joy, our pain. They ail show as their own character their direct- ness towards (intentional) objects. The large school of Brentano, with its outstanding members Anton Marty, Alexius Meinong, Kasimir Twardowski, Thomas G. Masaryk, Christian von Ehrenfels, Cari Stumpf, and Edmund Husserl, turned out to become the most influential one in the Habsburg empire where ail just named, except Husserl, were renewing philosophy from the eighties of last century on. The rich topical variety and the method provided by Brentano himself gave enough ground to form a kind of scholastic, using the best of the neo-Aristotelianism of the 19th century and defending a scientific and objectivistic program of phi­ losophy. When Bertrand Russell published an article in 1924 in The Dial on the ,JPhilosophy in the Twentieth Century", he classified this „new philosophy" by attributing to it two aims : „analysis as method and pluralism as a metaphysic" ; to this characteristic he added that this philosophy is „not compatible with Kantian and Hegelian idealism because it rejects the logic upon which those Systems are based" [Russell 1924, 450-466]. As typical of this „new philoso­ phy" Russell mentioned that it conceives of ail knowledge as scientific to be verified and proved by scientific methods. Another spécial concern of this new philosophy mentioned by Russell is the pre-occupation with logic and mathe- matics and under thèse especially with the logical analysis of propositions. The very basis for this évaluation was Russell's profound knowledge of Meinong's philosophical work which confronted him with the idea that it is our narrow-minded concentration on the realm of the real which prevents us to accept the thèses that also the non-existent and even the impossible objects must hâve some kind of being in order to be thought about in order to enter our judgements etc. While in the world of Meinong it is true that „the golden moun- tain is golden" and that „the round square is round" the robust sensé of reality of Russell had to claim the non-existence of the golden mountain while the contradictory prédications to an impossible object like the round square were nothing but logical howlers. Russell therefore had developed his theory of defi- nite description in 1905 to reject Meinong's theory of non-existing objects. He thought of thèse object-theoretical propositions like the round square, which do not exist. They lead to absurdities which his theory could avoid. But he under- lined that „absurdities are the experiments of the logician" [op. cit. 462]. 98 Rudolph Haller One of the important features of philosophy in the Austrian Empire was that the strong relation to the empiristic tradition remained alive ail the time at least since Theodor Gomperz, the father of Heinrich Gomperz, started the édi­ tion of J.St. Mill's works to be translated into German. And actually also Brentano himself was eager to get in personal contact with Mill. And it was him who directed also Meinong's interest to English philosophy, to study Hume's theory of relation to criticise Hume's theory of abstraction.1 As it is known, the lively discussion between Meinong and Russell culminated such that fifty years after Meinong's death Gilbert Ryle could déclare that Meinong's theory of objects is dead and will never be resurrected. Ryle had only overlooked that at the very time of his judgement the rise of the new born existence-free logic and of Meinongian semantics was already under way2 However, this is another story. There is no doubt that in present-day philosophy we hâve to acknowledge a strong interest in the philosophical théories of Brentano, Meinong and other members of this school, like Christian von Ehrenfels or Kasimir Twardowski. And this has to do with the fruitful research program which Brentano had to offer. According to Brentano, the source of knowing our inner world, the realm of the psychic phenomena is inner perception, the only kind of perception which should provide us with évident knowledge, because, according to Brentano, in ail our psychic activities is included also the évident consciousness of thèse psychic phenomena. Thus Brentano is eager to provide a gênerai theory of ail kinds of objects of the inner world, an ontology and theo­ ry of catégories. The main division of two parts of the new science of psychology distin- guishes between that theory which investigates the ultimate psychic parts which is such that out of them the totality of the psychic phenomena can be reconstructed. Brentano thinks that his procédure could lead to a kind of a cha- racteristica universalis, as Barry Smith has called it. The other part, genetic psy­ chology, should carry out the task to investigate the laws and provide the expia- nations for their coming and going, their causal relations. In a certain sensé it is true that Brentano throughout his many philosophical changes remained an Aristotelian. This can easily be seen when we take a look at his readings of Poincaré and his différent critical notes on Poincaré's philosophy of science. Especially concerning Poincaré's theory of space and his geometrical views, Brentano remains mainly négative. At différent periods of his philosophical development Brentano dedicated much time and work to form a theory of space 1 Vide: A.Meinong, „Hume-Studien I: Zur Geschichte und Kritik des modernen Nominalismus" (1877). In: Gesamtausgabe Bd.l, Abhandlungen zur Psychologie, Graz 1969 2 Vide: Jenseits von Sein und Nichtsein.