Mill’s observations about slavery in this passage speak to the dangerous extent to which cruel, unjust institutions can be allowed to survive due to people’s moral inertia and complicity. As he points out, slave-owners would work slaves “literally to death,” highlighting the brutality of this system. The fact that many in England were critical of slavery yet still essentially permitted it to exist demonstrates the power of social institutions to endure even if most people do not actively support them. The same logic, Mill implies, can be applied to the subjugation of women.