Cultivating a broad range of pursuits was once seen as the richest way to live, and the surest path to Great discoveries.
Even today, in a time where the model of efficiency via hyper-specialisation has shifted our focus from ideas to output, the envelope-shifters we most look up to are polymaths. (Steve Jobs and Elon Musk spring to mind.)
I travelled with Bedouin in the Western Desert of Egypt. When we got a puncture, they used tape and an old inner tube to suck air from three tyres to inflate a fourth. It was the cook who suggested the idea; maybe he was used to making food designed for a few go further.
If it weren't for an actress and a pianist, GPS and WiFi might not exist. In the late 1930s and early 40s, Hedy Lamarr was already the toast of Hollywood, famed for her portrayals of femme fatales. Few of her contemporaries knew that her other great passion was inventing.
The polymath not only moves between different spheres or different fields and disciplines, but seeks fundamental connections between those fields, so as to give them a unique insight into each of them.