Is there anything you believe for completely arbitrary reasons and is there anything wrong with that if so? “Arbitrary” is one of those funny little words that has, over time, just about flipped its meaning. It comes from the Latin for coming or going to serve as a judge—or a witness. Now it very nearly means something serving as the opposite, as a “reason” without a reason, either abstract, in the manner of law, or particular, in the manner of testimony. “That’s just, like, your opinion, man...”