The consensus theory is well known. According to consensus theory, contract is the product of the consensus or “meeting of the minds” of contracting parties; if there is no consensus, there is no contract. Today, even after repeated challenges, consensus theory continues to be important and even essential in many approaches to contract.

Recalling his years as a student at the Columbia Law School, William O. Douglas (1898–1980) wrote that one of his teachers, Thomas Reed Powell (1880–1955), was “then an iconoclast. He was the offbeat intellectual who could cut the Supreme Court into ribbons in any field of constitutional law.” Although the two men later drifted apart, they remained good friends for more than two decades, and their correspondence is a remarkable window not only into their agile and creative minds, but into the constitutional and academic issues of their times as well.