"Eles são brancos e se entendem". (Brazilian idiom)
Vienneau quotes from "Narrative of the Life of Frederick Douglas":
"When Colonel Lloyd's slaves met the slaves of Jacob Jepson, they seldom parted without a quarrel about their masters; Colonel Lloyd's slaves contending that he was the richest, and Mr. Jepson's slaves that he was the smartest, and most of a man."Apparently, Brazilian slaves could be a bit more cynical than their North American counterparts. One of their pieces of folk wisdom (the opening quote) suggests that; surprisingly, it endured and entered contemporary popular speech.
There are different stories about the origin of the idiom. There is not even a canonical form (the one presented above is one among many, with slightly different wordings, meanings, and connotations); literally, this version means "they are white, and understand each other".
More broadly, the idea is that upon witnessing important people's petty spats, the little people should not get too involved: whatever the brouhaha between grandees, at the end of the day they understand each other.
Apply it to the endless squabbles among Keynesian economists.
02/02/2016. Bang on cue to demonstrate why we should not take Keynesian economists too seriously comes the "Very Serious People" controversy (h/t Ramanan): after years mercilessly whipping Austerians as self-appointed "Very Serious People" who unfairly marginalise Keynesian underdogs -- like himself -- Paul Krugman appoints himself "Very Serious Person" and proceeds to marginalise Sanders' supporters.
To maintain my own impartiality in the Keynesian holy war, after pointing to the heretical Krugman, I'll highlight that among the dinky di Keynesians the idea of "pluralism in economics teaching" seldom survives beyond the Real-World Economics Review.
[A] "Whipping an Enslaved Male, Serro Frio, Brazil", by Carlos Julião. The Atlantic Slave Trade and Slave Life in the Americas: A Visual Record. Public Domain. Source: Wikimedia.