Saul Perlmutter is a 2011 Nobel Laureate, sharing the prize in Physics for the discovery of the accelerating expansion of the universe. He is professor of physics at the University of California, Berkeley, and a senior scientist at Lawrence Berkeley National Laboratory. He is also the leader of the International Supernova Cosmology Project, director of the Berkeley Institute for Data Science, and executive director of the Berkeley Center for Cosmological Physics. Robert MacCoun is a social psychologist and public policy analyst who is currently James and Patricia Kowal Professor of Law at Stanford University and a Senior Fellow at the Freeman Spogli Institute for International Studies. His previous book with Peter Reuter, Drug War Heresies: Learning from Other Vices, Times, and Places is considered a landmark scholarly analysis of the drug legalization debate. His publications and expert testimony on military unit cohesion were influential in the 1993 and 2010 policy debates about allowing gay and lesbian people to serve openly in the US military. John Campbell is Willis S. and Marion Slusser Professor of Philosophy at the University of California, Berkeley. He has held Guggenheim and NEH Fellowships and served as President of the European Society for Philosophy and Psychology. Campbell is the author of Past, Space and Self (1994), Reference and Consciousness (2002), Berkeley's Puzzle, co-authored with Quassim Cassam (2012) and Causation in Psychology (2020).