What is the author's tone in the autobiography, The Heart and the Fist?

Eric Greitens divides his autobiography “The Heart and the Fist: The Education of a Humanitarian, The Making of a Navy SEAL” into three primary parts, with each part being subdivided into chapters. Each part involves a specific portion of Eric’s life relating to his education as a humanitarian and making as a SEAL, and each chapter deals with a specific event, or series of events relating to the overall part. In Part I: Mind and Fist, Eric recounts his early life, early education, and boxing days – the mind (education) and the fist (boxing). In Part II: Heart and Mind, Eric recounts his continuing education and firsthand experience in helping refugees – the heart (humanitarian work) and the mind (education). In Part III: Heart and Fist, Eric recounts his work to become a Navy SEAL, and the humanitarian efforts made toward suffering people as a SEAL – the heart (humanitarian work) and the fist (service as a SEAL). These three parts are concluded by an Epilogue in which Eric describes his work in founding The Mission Continues, and an Afterword in which Eric speaks of the death of Bin Laden and the work The Mission Continues has done up through the beginning of 2012.