Can you imagine if everyone had a negro slave at home doing everything for them? If black lives didn’t matter
and we could treat them however we wanted to treat them. No, because that would be against all our morals and socials values, or at least I think so.
There were a lot of protesters against that principle, primarily people from the northern states who claimed, that slavery was wrong principally, morally, politically, and socially.
In defense to their claims, he compared his principles to other principles by famous philosophers/scientists.
He argued that people didn’t acknowledge them at first, but later found them to be true e.g. his comparison to Galileo in question 2.