The question of Einstein's rejection of the November tensor is re-examined in light of conflicting answers by several historians. I discuss these conflicting conjectures in view of three questions that should inform our thinking: Why did Einstein reject the November tensor in 1912, only to come back to it in 1915? Why was it hard for Einstein to recognize that the November tensor is a natural generalization of Newton's law of gravitation? Why did it take him three years to realize that the November tensor is not incompatible with Newton's law? I first briefly describe Einstein's work in the Zurich Notebook. I then discuss a number of interpretive conjectures formulated by historians and what may be inferred from them. Finally, I offer a new combined conjecture that answers the above questions.It is funny how many papers are devoted to trying to figure out how Einstein discovered general relativity, without considering the obvious hypothesis that he got the crucial ideas from others.
General relativity is just the obvious generalization of special relativity to gravity, once you accept the role of the Ricci tensor. How did Einstein reach that conclusion? Well, Grossmann, Levi-Civita, and Hilbert told him so, and after a couple of years he accepted it. What is the big mystery?