A popular theme in science fiction is the eerily lifelike robot: a piece of machinery so well engineered that its outputs pass for genuinely human behaviors. Technology is not yet so advanced, but these robots might cause us to wonder how we could possibly justify our belief in the minds of others. You’re most likely sure that your family, friends, and boss are really people just like you, with similarly rich inner mental lives. But how can you be so sure? If we only have access to our own private thoughts, can we ever know that our minds are not unique? I think, therefore I exist – but what about everybody else? John and Ken step outside themselves with Anita Avramides from the University of Oxford, author of Other Minds.