If there is a moral compass, how do we know what is the North and South? What is right and wrong? If right and wrong are culturally variable, then the only arbiters of right and wrong are mere preference, or alternatively, force. Cooperation, or niceness, says Alex Rosenberg, was essential to our evolution from being at the bottom of the food chain, to arriving at the top. But are we agreed on who we should be nice to, and when? Dr Gwen Patton grew up in the racially segregated America of the 1950s. To her the limits of niceness were clear, because people chose who they would be nice to, and who not. She became involved, as a young girl, in the Alabama bus protests, driven by a sense that we are all God's children. In discussion with Frans de Wall, Ard says he needs an absolute logical, rational source for moral judgements. If morality is just grounded in passions, you can manipulate those passions. David disagrees. He thinks we all work out our own truths. Ard argues that universal morality then would depend merely on power.