Themis, Dike’s mother, was goddess of divine justice, morality amongst the gods. Dike, on the other hand, was to rule over human justice.
Dike’s name, Δικη, in Ancient Greek meant behaviour in accordance with nature, without a moral connotation. Later, the name came to be more closely identified with “justice”. In Roman mythology, Dike was identified with Justitia (though so was Themis). The Roman version of this goddess has become a symbol of justice in Western civilization, being depicted with a blindfold, sword and scales.