"Lady Justice (Iustitia, the Roman Goddess of Justice and sometimes, simply "Justice") is an allegorical personification of the moral force that underlies the legal system....

"Justitia is most often depicted with a set of weighing scales typically suspended from her left hand, upon which she measures the strengths of a case's support and opposition. She is also often seen carrying a double-edged sword in her right hand, symbolizing the power of Reason and Justice, which may be wielded either for or against any party.

"...Lady Justice is often depicted wearing a blindfold. This is done in order to indicate that justice is (or should be) meted out objectively, without fear or favor, regardless of the identity, power, or weakness: blind justice & blind equality."

[From Wikipedia.]