Liberty in the private sphere of life is matched by equality in the public sphere; political emancipation means that all are treated equally. Individual liberties, when applied with reciprocity, become public rights. When these are not applied equally to all people, then there is a population that requires emancipation. From this promise of modernity, moral impetus was given to the great acts of emancipation; freedom of religious belief, disbelief, and practise, women's suffrage and rights, and the abolition of slavery, and apartheid - that is the practise of discrimination on the basis of race and sex. Increasingly, an equality of rights is being introduced on the consensual sexual orientations and their practises.
The concept includes the notion of isonomia (ἰσονομία "equality of rights"), as used by Herodotus (3.80) and Thucydides, who used it interchangeably with democracy in contrast with monarchy. e.g., Herodutus quoting Otanes c492BCE: "I vote, therefore, that we do away with monarchy, and raise the people to power. For the people are all in all."
Aristotle argued democracy and isonomia need to be combined: "Democracy arose from the idea that those who are equal in any respect are equal absolutely. All are alike free, therefore they claim that all are free absolutely... The next is when the democrats, on the grounds that they are all equal, claim equal participation in everything." (Politics, Book V)
Further, the highest possible levels of education is requisite for members of a society to make rational choices. This is recognised by Robert Charles Winthrop when he wrote; "Slavery is but half abolished, emancipation is but half completed, while millions of freemen with votes in their hands are left without education."