When I was PhD student at Cambridge, a supervisor once told me to “beware the sound of one hand clapping.” By that he meant that it is impossible to assess an argument without assessing the counterarguments. Later, as a college professor, I developed a corollary to this principle. I used to tell my own students that the best way to weigh an argument was to see how well it withstood critical scrutiny and how well its proponents could respond to the strongest objections to their case. Medieval philosophers presupposed this principle in their disputational method. They would first make an
...more
