"Mattis is a graduate of the U.S. Marine Corps Amphibious Warfare School, U.S. Marine Corps Command and Staff College, and the National War College. Mattis is also noted for his intellectualism and interest in military history, with a personal library that once included over 7,000 volumes, and a penchant for publishing required reading lists for Marines under his command. Mattis is a life-long bachelor,who has never been married and has no children. He is nicknamed "The Warrior Monk" because of his bachelor life, and the fact he devoted his life to studying and fighting war. He is known for the intellectual rigor he puts on his Marines and his belief in risk-management, and in the need for troops under his command to read widely about the cultural norms and history of the area they are sent to, as he himself does. Before deploying to Iraq, Mattis ensured his troops were given courses on Arab culture and cultural sensitivity classes."