>He thought some humans were slaves by nature and women were naturally inferior to men.

These are unfortunately still all too common beliefs. The latter has mostly been folded into racial essentialism and racial realist beliefs, because slavery is no longer legal (13th amendment loophole notwithstanding) and you can still find people arguing women are intellectually inferior and incapable of rational thought.

The whole anti-DEI movement is based on the premise that non-whites and women categorically don't deserve the same status in the workforce as white men, and the only reason they have "equality" is due to anti-white racism.