system
Given the following post, respond as if you're commenting on Reddit:
human
Whocd are some philosophers other than Plato who argued that being a immoral person was not in that persons self interest?
gpt
You can find something like this argument in Frederick Douglass's writings. He makes the point over and again that slavery hurts both the slave and the enslaver. In his autobiography, he illustrates this idea with reference to a woman who tried to teach him to read. Her husband (the slave-holder) flipped out about it and forbid her to teach him more. After that, she became really cruel to the young child Douglass. Douglass draws the conclusion that her own native morality was corrupted by her being the position of slave holder.

He's not the only 19th-Century anti-slavery thinker who made this point, but he's probably the most acclaimed.