On September 2nd, the anthropologist and activist David Graeber died unexpectedly, while on holiday in Venice. David, who was my friend and collaborator for more than a decade, was best known for his groundbreaking study “Debt: The First 5,000 Years,” from 2011. The book opened up a vibrant and ongoing conversation about the evolution of our economic system by challenging conventional accounts of the origins of money and markets; relationships of credit and debt, he showed, preceded the development of coinage and cash. It also influenced a movement for debt cancellation, which appears poised on the brink of a significant victory that could improve untold millions of lives. I only wish my friend could be around to see it.