Samuelson's Text Book the War Ends

Samuelson was given a lot of credit also for the mathematization of economics. Was that part of what made the text book itself so compelling, or was that part of a different intellectual project samuelson pursued throughout his life? It was kaines who was the mathematician. He never was an economist, ever. And it's because of mathematics that he was able to write the general theory in order to describe the the fluctuating parts and bits and pieces, and how the various changes when working together, made some sense.