Plenty of people at the time thought slavery was evil. Franklin was even one of them, calling it "cancer." He said this while still owning slaves, which is rather peculiar, but people are complicated.
In this century we have a word for that kind of talk by slaveholders who professed some longing for abolition (Franklin. Jefferson, Washington, John Jay) but did not really wanna be inconvenienced: trolling.
In this century we have a word for that kind of talk by slaveholders who professed some longing for abolition (Franklin. Jefferson, Washington, John Jay) but did not really wanna be inconvenienced: trolling.