Carlo Rovelli (Univ. of Aix Marseilles) gives a talk at the Workshop on "Why trust a Theory?" (7-9 December, 2015) titled "Non-empirical Confirmation: Just a Cover-Up for the Failures of String Theory?". Abstract: Fundamental physics has changed from a field capable of spectacular successful predictions (electromagnetic waves, black holes, antiparticles, just to name a few...) to a depressing sequence of failed predictions: low-energy supersymmetry being the most recent and burning. Why? I will consider the possibility that the last generation of theoretical physicists has modified the practice of scientific method. Unproductively.