Abstract
Given the sharp distinction that follows from Hume’s Fork, the proper
epistemic status of propositions of mixed mathematics seems to be a mystery.
On the one hand, mathematical propositions concern the relation of ideas. They
are intuitive and demonstratively certain. On the other hand, propositions of
mixed mathematics, such as in Hume’s own example, the law of conservation of
momentum, are also matter of fact propositions. They concern causal relations
between species of objects, and, in this sense, they are not intuitive or demonstratively
certain, but probable or provable. In this article, I argue that the epistemic
status of propositions of mixed mathematics is that of matters of fact. I wish to
show that their epistemic status is not a mystery. The reason for this is that the
propositions of mixed mathematics are dependent on the Uniformity Principle,
unlike the propositions of pure mathematics.