If anyone has any clue about what schizophrenia entails, he would realize that Nash was greater than Einstein.
Our society appreciates physics more because it is more intuitive and a lot of people can claim to somewhat understand what is going on. Math, on the other hand, is esoteric to most people. The guy was a sheer genius…
Mathematics is all about proving theorems. You assume certain foundations, known as axioms, and build your own world out of it. If another person builds upon the same foundations, he would come to the same conclusions as the first person. In other words, Math is a world unto itself, and what happens in Mathematics, the theorems that currently exist, may be useful in Physics, Economics, Biology, etc, etc three hundred years later.
As such, Nash may have advanced the world much more than Einstein. We will only find out when Nash’s work becomes applicable to the real world 300 years later.