Equality, a basic philosophical idea in modern Western thought, has become a fundamental principle in contemporary legal systems. Philosophy of law offers therefore a significant perspective in order to consider some theoretical issues arising from this concept. Is equality of human beings a moral assumption or a political goal? What kind of relationship exists between equality and diversity? Are they facts or values? What inequalities are unjust? What does it mean, from a legal point of view, to treat people "as equals"? The prohibition of discrimination can be justified in the name of the principle of equality as a foundation of the individual rights or as a foundation of the political community.