If one is forced to answer such a useless question, then I don't see how there can be any other choice but Keynes. He invented Macroeconomics! That not only dispensed with Hayek's problem -- he never succeeded in unraveling the complications of his micro approach to economics -- but it led the way forward. Keynes realized that the only way you could get anywhere was to look on a complicated economy in terms of what is true in aggregate.
He correctly forecast the disastrous situation to come from the punitive Treaty of Versaille. And, as a young man, he was so distraught over the negotiations, he took to his quarters near the Bois de Boulogne outside Paris, rather then participate further. (Lloyd George led the British delegation).
At Bretton Woods he correctly foresaw the difficulties that would come from choosing a single commodity based currency, the U.S. Dollar, as a reserve currency. He advocated instead, to no avail, for a reserve currency based on a basket of sovereign currencies.
Were he alive today he would, I am quite sure, align himself with the MMT economists. He had the quality of most great statesmen, economists and scientists of being so sure he was right that he could be insufferable; yet, unlike not a few of these brilliant minds, he avoided tarnishing his reputation with a single great blunder.
I am resolute here. I simply don't see how, if one is forced to choose only one economist, one cannot settle on Keynes.
