That’s the neat part, it’s not!
Maybe I’m too pessimistic, but I don’t think this kind of point is debatable. A person who does not share a fundamental care for humanity cannot be debated. The only thing to do is to take away their ability to do harm and hope that interacting with the world without the power to do harm makes them wiser and kinder (assuming that the way you took away their ability to do harm wasn’t a guillotine).
I’m always shocked to hear him speak about stuff because he sounds so perfectly well-adjusted, empathetic, and normal. lol that’ll show us to judge someone who makes an ascii game all night every night and has plywood over his window so he can sleep all day!