A quarter century into the modern era of computing, two young assistant professors joined forces with the legendary Alan Perlis, one of the founding fathers of American computer science, and would publish a paper challenging the conventional wisdom that computer programming should be formal and mathematical. It was a shot across the bow to Edsgar Dijkstra, Tony Hoare and many others who sought the certainty of mathematical proofs of software correctness. The paper would become a lightning rod for a debate that would continue for the better part of four decades.