Pain is a feeling that’s nearly impossible to quantify – even the oft used 1-10 scale is tied to an individual’s perception. This hour, we’ll talk about how our inability to agree on this most basic feeling has led to differences of opinion on legal issues with Keith Wailoo, vice dean of the Woodrow Wilson School of Public and International Affairs at Princeton University. He’s the author of “Pain: A Political History” (Johns Hopkins University Press).