Quite appropriately, they share a birthday today.
The other day I posted an Akerlof quote about how one advantage economists have over non-economists is a deeper appreciation of general equilibrium. There was some speculation on twitter by Unlearningecon and others about whether I was just sharing it or whether I actually believe it.
I definitely believe it, and there are probably no better examples of the point than Adam Smith and John Maynard Keynes, who both really pushed the frontiers of economics by pointing out important general equilibrium phenomena and demonstrating that you can't just add up a lot of individual behavior and expect to understand aggregate behavior. In Smith's case he pointed out that even in a situation devoid of "benevolence" market economies make everyone better off. In Keynes's case, he pointed out individual decisions to guard their liquidity or to cut wages may, in the aggregate, produce results that hurt everyone because in the short run of a monetary economy output is typically demand-determined.
These are both general equilibrium insights and they are both points that people who have never taken the time to think about economics carefully have trouble accepting.