Piety (from the Latin pietas) is the feeling that leads man to love and respect others.
The actual meaning of the word mercy, that mercy, not the meaning of the term from which it derives: the piety of the ancients was indeed the religious devotion, the patriotic feeling of love and respect towards the family and the intrinsic value and hierarchical it represented in the Hellenic world.
Aeneas was nicknamed the pious not because he was good and merciful, but only because he was not particularly devoted to the gods, as seen by the blind trust he put in their predictions, but also because it perfectly embodies the values of respect for family unity, as sees the Aeneid, when fleeing from Troy, Aeneas when you load is the son that his father Anchises.
Aeneas always obey the gods and fate, shifting the emphasis from the personal experiences such as love for Dido. The reason of piety is evident in his deeds, as if in search of his old father and takes him on his back while fleeing. Here the attitude of "pity" of the Trojan hero is the respect of traditional values such as family, home and religion.
The meaning of the term approached its current mercy with Christianity, for whom compassion is an attribute of God.
See Also: idul fitri, hamper hari raya, hari raya hampers