"My good reason to carry a knife is that God gave me rather weak teeth and rudimentary claws in an evolutionary trade-off. The hairy-armed person who figured out how to put an edge on a suitable rock made it possible for us to be recognizably human in the first place. I wear a wristwatch whether or not I have an appointment to keep, and I carry a pen and/or pencil because I am a literate person whether or not I have a specific writing task ahead of me, and I carry a knife because I am a human and not an ape."

- James Mattis