In the New Yorker, Ryan Lizza writes:
Larry Summers and the White House economic team: Even in the culture of ferocious debate that characterized the economics departments of M.I.T. and Harvard, Summers stood out for his confrontational approach. “Larry’s impressed by no one and never was,” James Hines, a former Harvard economist who now teaches at the University of Michigan, said:
There was an awful lot, especially at Harvard in those days, of being impressed by people for the titles that they held, and none of that would ever work on Larry. Graduate students like me gravitated to him specifically for that reason.
Hines added that debate in economics, unlike the humanities, is “a very rough back-and-forth. And, oh my God, Larry put everybody else to shame. He was vicious among economists”...
A better way to put it is that Larry Summers was and is impressed by your good ideas, but not at all impressed by whatever reputation you have. If he thinks your ideas are good, he will be vicious toward them--but not vicious against you--because the best ideas are those that can withstand the most profound and searching and aggressive criticisms.
Go into a meeting with Larry Summers thinking that he is going to be nice and friendly towards your ideas because you are young and insecure or because you are olders and have a gold-standard reputation and deserve deference, and you will be badly shocked. The better he thinks your ideas are, the more viciously he will criticize them--but that is a sign of respect, not of contempt.
After a while, the thing we graduate students came to dread was the possibility that you would throw out what you think is your best idea, and he would sit for thirty seconds and then say: "OK. Yeah. Been working on anything else?"