The conflict is indeed irresistible.

The chief interest in the American crusade against slavery arises from its relation to this general world conflict between liberty and despotism.
The Athenians could be democrats and at the same time could uphold and defend the institution of slavery.

They were committed to the doctrine that the masses of the people were slaves by nature.

By definition, they made slaves creatures void of will and personality, and they conveniently ignored them in matters of state.

But Americans living in States founded in the era of the Declaration of Independence could not be good democrats and at the same time uphold and defend the institution of slavery, for the Declaration gives the lie to all such assumptions of human inequality by accepting the cardinal axiom that all men are created equal and are endowed with certain inalienable rights, among which are life, liberty, and the pursuit of happiness.