Sam Harris speaks with David Edmonds about the life and philosophy of Derek Parfit. They discuss Parfit’s work on identity, time bias, the “non-identity problem,” population ethics and “the Repugnant Conclusion,” the ethical importance of future people, Effective Altruism, moral truth, and other topics. If the Making Sense podcast logo in your player is BLACK, you can SUBSCRIBE to gain access to all full-length episodes at samharris.org/subscribe.   Learning how to train your mind is the single greatest investment you can make in life. That’s why Sam Harris created the Waking Up app. From rational mindfulness practice to lessons on some of life’s most important topics, join Sam as he demystifies the practice of meditation and explores the theory behind it.