Mirja Helena Hartimo

The paper examines Husserl’s phenomenology and Hilbert’s view of the foundations of mathematics against the backdrop of their lifelong friendship. After a brief account of the complementary nature of their early approaches, the paper focuses on Husserl’s Formale und transzendentale Logik viewed as a response to Hilbert’s “new foundations” developed in the 1920s. While both Husserl and Hilbert share a “mathematics first,” nonrevisionist approach toward mathematics, they disagree about the way in which the access to it should be construed: Hilbert wanted to reach it and show it consistent by his formalism on the basis of sensuous signs, Husserl held that there should be a reduction to elementary judgements about individuals. Husserl’s reduction does not establish the consistency of mathematics but he claims it is important for the considerations of truth.

The paper aims to capture a form of naturalism that can be found “built-in” in phenomenology, namely the idea to take science or mathematics on its own, without postulating extraneous normative “molds” on it. The paper offers a detailed comparison of Penelope Maddy’s naturalism about mathematics and Husserl’s approach to mathematics in Formal and Transcendental Logic. It argues that Maddy’s naturalized methodology is similar to the approach in the first part of the book. However, in the second part Husserl enters into a transcendental clarification of the evidences and presuppositions of the mathematicians’ work, thus “transcendentalizing” his otherwise naturalist approach to mathematics. The result is a moderately revisionist view that takes the existing mathematical practices seriously, calls for reflection on them, and eventually gives suggestions for revisions if needed.

ABSTRACT. The paper compares the views of Edmund Husserl (1859-1938) and Charles Sanders Peirce (1839-1914) on mathematics around the turn of the century. The two share a view that mathematics is an independent and theoretical discipline. Both think that it is something unrelated to how we actually think, and hence independent of psychology. For both, mathematics reveals the objective and formal structure of the world, and both think that modern mathematics is a Platonist enterprise. Husserl and Peirce also share a teleological conception of the development of mathematics: both view it to evolve towards a goal. This is where the primary difference between the two can be found: while for Husserl the goal of mathematics is to characterize definite manifolds, for Peirce it is to discover the real potential world as expressed by his conception of continuum. Peirce elaborates the continuum with the notion ‘potential aggregate,’ a totality of the series of uncountable sets (each created by Cantor’s theorem) briefly discussed and compared to Husserl’s notion of definite manifolds.