NEW YORK TIMES BESTSELLER A masterpiece of warrior wisdom: how to be resilient, how to overcome obstacles not by "positive thinking" or self-esteem, but by positive action. The best-selling author, Navy SEAL, and humanitarian Eric Greitens offers a self-help book unlike any other. "Eric Greitens provides a brilliant and brave course of action to help navigate life's roughest waters."—Admiral Mike Mullen, seventeenth chairman of the Joint Chiefs of Staff In 2012, Eric Greitens unexpectedly heard from a former SEAL comrade, a brother-in-arms he hadn't seen in a decade. Zach Walker had been one of the toughest of the tough. But ever since he returned home from war to his young family in a small logging town, he'd been struggling. Without a sense of purpose, plagued by PTSD, and masking his pain with heavy drinking, he needed help. Zach and Eric started writing and talking nearly every day, as Eric set down his thoughts on what it takes to build resilience in our lives. Eric's letters — drawing on both his own experience and wisdom from ancient and modern thinkers — are now gathered and edited into this timeless guidebook. Greitens shows how we can build purpose, confront pain, practice compassion, develop a vocation, find a mentor, create happiness, and much more. Resilience is an inspiring meditation for the warrior in each of us. "This book is a gift not only to Greitens's comrades-in-arms, but to readers everywhere."—Publishers Weekly, starred review