The objects shown here are from different periods, but they have one thing in common: they all depict a set of scales. Balances were used in ancient Egypt and associated with the Judgement of Osiris. The dead man, carrying his heart in his hand, stands before the court of Osiris, accompanied by a goddess. There the heart is placed on the right scale and weighed against the feather of Maat, goddess of truth, on the left. Thoth, with the head of an ibis, records the result of the weighing, while the jackal-headed Anubis watches the balance needle. Osiris, holding the crook and flail as symbols of his authority and power, presides over the judgement with his wife Isis, while the Devourer of Hearts, a woman with the head of a crocodile, awaits the outcome at their feet. If the heart weighs more than the feather because the dead man is unable to justify his actions in life, his heart will be devoured and his death will be eternal.
Scales were also a symbol of justice in the classical world, as evidenced by an Etruscan mirror where we see the god Hermes holding a set of scales on which he weighs men to determine their fate, and in the Middle Ages, when the Archangel Michael was often depicted weighing souls in the balance to decide whether they would be saved or doomed. During this time, scales were still associated with the idea that the weighing of souls preceded the determination of their immortal destiny.
This symbol has endured to the present day. Since the Renaissance, justice is often personified as a blindfolded woman with a sword in one hand and a set of scales, representing balance and fairness, in the other.