=25.= The religion of the Greeks, properly so called, consisted in reverence toward a moral Ruler of the world, ever present and actively concerned in human affairs; and in obedience to him by truthfulness in thought, word, and deed. Zeus himself was believed to watch over the sacred performance of all oaths. Athena was the divine Wisdom, especially as exercised in civil affairs. Nem´esis was the divine Justice, as heard either in warnings of conscience within or the reproaches of the world without. The Erin´nyes, or as they were flatteringly called, Eumen´ides,[36] were the avengers of crime, older than all the Olympian divinities, and dreaded alike by gods and men. The cries of the injured aroused them from their dark abode in Tartarus; and to the guilty man they appeared as fierce, implacable furies, with flaming eyes and extended talons, who never slept, but walked or waited constantly by his side from the moment of his crime till its punishment; while to the innocent victim, whom they avenged, they wore the form of serene and stately goddesses, with faces beautiful though stern. =26.= At a later period, new elements entered into the religious life of the Greeks, through their intercourse with other nations, especially with Egypt, Asia Minor, and Thrace. The most important of these was the idea of purification for sins, which was unknown to Homer and Hesiod, and was probably borrowed from the Lydians. The earliest sacrifices were merely expressions of gratitude, or means of obtaining the favor of the gods, and had nothing of the character of sin-offerings. In case of crime, it was impossible to turn aside the wrath of the Eumenides, either by prayers or sacrifices; the guilty person must suffer the extremest consequences of his guilt. But under the new system it was believed that the divine anger might be averted, and the stain of sin removed. Persons guilty of homicide, whether intentional or accidental, were excluded from the society of man and the worship of the gods until certain rites had been performed. In earlier times, a chief or king might officiate in the ceremony of purification, but later it was intrusted to priests, or to persons supposed to be specially marked for the favor of heaven by holiness of life. In case of public calamity, such as plague, famine, or defeat in war, whole cities or states underwent the process of purification, with a view to appease the supposed wrath of the gods for some hidden or open crime.