Counter to the impression given by George Ellis and Joe Silk, I have never used or endorsed the slogans “elegance will suffice” and “post-empirical science” regarding theories in fundamental physics (Nature 516, 321–323, 2014). In fact, both contradict my position.

I do not think that criteria such as simplicity or elegance provide a workable basis for judging a theory's chances of viability. I seek arguments that are more reliable.

Nor is my concept of non-empirical theory confirmation driven by a wish to declare empirical data obsolete. Rather, it aims to account for the actual situation in modern fundamental physics by extending the concept of theory confirmation while preserving the primacy of empirical data.

A theory's non-empirical confirmation relies on experimental confirmation in three ways. First, a theory's viability is defined in terms of its empirical confirmation. Second, non-empirical confirmation will always remain weaker than conclusive empirical confirmation. And third, non-empirical confirmation relies on the observation that related theories in the field were empirically confirmed.

Terminating empirical confirmation in a research field would thus eventually destroy the basis for non-empirical confirmation as well.