From the The Last Days of the Polymath by Edward Carr:
The question is whether their loss has affected the course of human thought. Polymaths possess something that monomaths do not. Time and again, innovations come from a fresh eye or from another discipline. Most scientists devote their careers to solving the everyday problems in their specialism. Everyone knows what they are and it takes ingenuity and perseverance to crack them. But breakthroughs—the sort of idea that opens up whole sets of new problems—often come from other fields.
Perhaps we need a return to the Renaissance ideal.