In Chapter 10 of David Goggins' Can't Hurt Me, Goggins discusses the role of discipline in achieving success and overcoming obstacles. He describes discipline as the ability to control your thoughts, actions, and emotions, and offers practical advice for developing discipline, including the importance of setting goals, creating routines, and practicing self-control. Goggins also shares his own experiences of developing discipline, including his experiences in the military and his training for and completion of the Badwater Ultramarathon. He emphasizes that discipline is not just about following rules and regulations, but about taking control of your life and making the choices that will help you achieve your goals.