The liberal and radical thinkers of the European Enlightenment argued that human nature requires liberty and for this reason society should be made more democratic and egalitarian.
Their conservative opponents argued that human nature requires order and hierarchy and for this reason society should be based on traditional forms of dominance.
I think they were both wrong. If there was ever a social order for which we were physically adapted, it was that which prevailed among Palaeolithic humans. But our human nature makes us social and cultural beings. And our sociocultural evolution has taken us so far away from the Palaeolithic world that there is no going back.
We live in a permanently far-from-equilibrium state; no social reform or revolution will bring us to an equilibrium prescribed by some essential human nature.
What this means for socialism is that we cannot simply tear down oppressive structures and expect egalitarian ones to replace them automatically, through the negation of the negation. The classless society must be constructed.