In 1868 Beltrami published a paper ""Saggio di interpretazione della geometria non-euclidea" that seems to have led to the formalist philosophy of mathematics.
But what was written exactly what were the comments on it and how this it all evolve it into formalism?
I would like to read a book that does contains translations of the papers that were involved, with mathematical AND philosophical explanations.
Most books on formalism only pay lipservice to the geometrical history of formalism, I would like a book that explains it all