# A Dilemma for Mathematical Constructivism

*Axiomathes*:01-10 (2020)

**Abstract**

In this paper I argue that constructivism in mathematics faces a dilemma. In particular, I maintain that constructivism is unable to explain (i) the application of mathematics to nature and (ii) the intersubjectivity of mathematics unless (iii) it is conjoined with two theses that reduce it to a form of mathematical Platonism.
The paper is divided into five sections. In the first section of the paper, I explain the difference between mathematical constructivism and mathematical Platonism and I outline my argument. In the second, I argue that the best explanation of how mathematics applies to nature for a constructivist is a thesis I call Copernicanism. In the third, I argue that the best explanation of how mathematics can be intersubjective for a constructivist is a thesis I call Ideality. In the fourth, I argue that once constructivism is conjoined with these two theses, it collapses into a form of mathematical Platonism. In the fifth, I confront some objections.

**Keywords**

**Categories**

(categorize this paper)

**PhilPapers/Archive ID**

KAHADF

**Upload history**

Archival date: 2020-02-04

View other versions

View other versions

**Added to PP index**

2020-02-04

**Total views**

100 ( #33,848 of 51,672 )

**Recent downloads (6 months)**

72 ( #6,982 of 51,672 )

How can I increase my downloads?

**Downloads since first upload**

*This graph includes both downloads from PhilArchive and clicks on external links on PhilPapers.*