031: Midweek Debrief - Where Did The Warrior Ethos Originate?

Where did the Warrior Ethos come from? Why would anyone choose this hard, dangerous life? What could be the philosophy behind such a choice?

https://www.trngcmd.marines.mil/Portals/207/Docs/SOI-W/MCTB/Student-Resources/Reference-2_The_Warrior_Ethos.pdf?ver=2018-10-12-135250-303