Brouwer and Husserl both aimed to give a philosophical account of mathematics. They met in 1928 when Husserl visited the Netherlands to deliver his Amsterdamer Vorträge. Soon after, Husserl expressed enthusiasm about this meeting in a letter to Heidegger, and he reports that they had long conversations which, for him, had been among the most interesting events in Amsterdam. However, nothing is known about the content of these conversations; and it is not clear whether or not there were any other (...) exchanges between them. The following is an attempt at some remarks on Husserl’s Philosophy of Arithmetic from an intuitionistic, by which I mean a Brouwerian, point of view. I will confine myself specifically to some intuitionistic musings on Husserl’s analysis of the concept of finite number, which he developed in his Habilitationsschrift of 1887, “On the Concept of Number,” and presented again in 1891 in the first four chapters of the Philosophy of Arithmetic. It will turn out that the intuitionistic account of number is very different from Husserl’s. For instance, they strongly disagree about the number 2. On the other hand, the roots of the projects of Husserl and Brouwer have much in common. Since this fact makes their disagreement pressing and lends it much of its significance, I will begin there. (shrink)

Recently discovered correspondence from Oskar Becker to Hermann Weyl sheds new light on Weyl's engagement with Husserlian transcendental phenomenology in 1918-1927. Here the last two of these letters, dated July and August, 1926, dealing with issues in the philosophy of mathematics are presented, together with background and a detailed commentary. The letters provide an instructive context for re-assessing the connection between intuitionism and phenomenology in Weyl's foundational thought, and for understanding Weyl's term ‘symbolic construction’ as marking his own considered position (...) in the foundational controversy of the 1920s. In addition, they reveal Weyl's hitherto unknown objections to Becker's detailed attempt (Mathematische Existenz, 1927) to ground the transfinite phenomenologically. (shrink)

This paper investigates Hermann Weyl’s reception of philosophical concepts stemming from the German Idealist Johann Gottlieb Fichte. In particular, Weyl’s ‘agens theory’ of matter, which he held around 1925, will be looked at. In the extant literature, the—admittedly also important—influence of Husserl on Weyl has mainly been addressed. Thus, apart from investigating some detailed Fichtean inheritances in Weyl’s concepts of causality, chance and continuity, the general difference which Weyl saw between the philosophies of Fichte and Husserl will also be discussed. (...) For Weyl this is above all a difference between an active constructivism and a rather passive phenomenological seeing. Further, the paper shows in some detail the way Weyl was drawn into a certain reading of Fichte by his Zurich colleague, the philosopher Fritz Medicus. The methodological frame of the paper is that of Konstellationsforschung, a historical and systematic approach which proves to be particularly fruitful when investigating a German Idealist context and which allows special attention to be given to the acting subjects within the constellation under investigation. Conversely, Weyl’s agens theory suggests amendments to this methodology.Keywords: Hermann Weyl; Fritz Medicus; Johann Gottlieb Fichte; Theory of matter; Activity vs. passivity; Konstellationsforschung. (shrink)

For some time now I have been arguing that Fichte's theory can be read as circular, antifoundationalist, and systematic, and further arguing that it is the source of an epistemological revolution in philosophy. Fichte and most of his interpreters mainly see him as carrying forward the critical philosophy. But I see him as breaking with it in crucial ways in a profoundly innovative theory. The aim of this paper is to pull together aspects of this argument in a single place (...) in order to describe Fichte's theory as I see it, using a wider range of texts than I have so far employed, drawing consequences that follow from my interpretation and responding to recent criticism of it. In so doing, I intend to reaffirm my conviction that the interest of Fichte's theory is not merely archival, something historians of philosophy are interested in because they cannot do philosophy, or something that philosophers might concern themselves with when they are not concerned with philosophy, but directly relevant to the contemporary discussion. But as I see it, the contemporary relevance of the Fichtean view largely depends on an unorthodox, anti-foundationalist reading of it. For if it is read in an orthodox, Cartesian, foundationalist manner, favored by most writers on Fichte, it has nothing or almost nothing to contribute to our increasingly anti-foundationalist debate on knowledge. (shrink)

Der weit gereiste Henrik Steffens schildert im vierten Band seiner zehnbändigen Autobiographie Was ich erlebte eine Begegnung mit Fichte gegen Ende des Jahres 1793.