No alternative to proliferation

TL;DR

This paper discusses the importance and risks of non-empirical theory assessment in fundamental physics, especially quantum gravity, emphasizing that proliferating theories is crucial when experimental tests are limited to prevent scientific stagnation.

Contribution

It critically examines the role of theory proliferation in non-empirical assessment and argues for its necessity in advancing physics when empirical data is scarce.

Findings

Proliferation of theories is essential in theory assessment.

Non-empirical assessment has both usefulness and dangers.

Theory proliferation helps prevent degeneration of research programs.

Abstract

We reflect on the nature, role and limits of non-empirical theory assessment in fundamental physics, focusing in particular on quantum gravity. We argue for the usefulness and, to some extent, necessity of non-empirical theory assessment, but also examine critically its dangers. We conclude that the principle of proliferation of theories is not only at the very root of theory assessment but all the more necessary when experimental tests are scarce, and also that, in the same situation, it represents the only medicine against the degeneration of scientific research programmes.