The current foundation of physics is not complete because two parts of it, namely General Relativity (GR) and Quantum Mechanics (QM), are not compatible. But why should we believe that it can be completed?  

**Question**: What are the best facts and citations about this belief (for, against or neutral)? 

Perhaps we can prove a result stating that any theory of physics from which we can recover GR and QM (and Standard Model) is inconsistent. But such a result would require to fix what we mean by "theory of physics" and "recover", which can be a deeper problem...