Albert Einstein's Methodology
  This paper discusses Einstein's methodology. 1. Einstein characterized his work as a theory of principle and reasoned that beyond kinematics, the 1905 heuristic relativity principle could offer new connections between non-kinematical concepts. 2. Einstein's creativity and inventiveness and process of thinking; invention or discovery. 3. Einstein considered his best friend Michele Besso as a sounding board and his class-mate from the Polytechnic Marcel Grossman, as his active partner. Yet, Einstein wrote to Arnold Sommerfeld that Grossman will never claim to be considered a co-discoverer of the Einstein-Grossmann theory. He only helped in guiding Einstein through the mathematical literature, but contributed nothing of substance to the results of the theory. Hence, Einstein neither considered Besso or Grossmann as co-discoverers of the relativity theory which he invented. 
Galina Weinstein
physics.hist-ph