This was the story round which centred the worship of the Sacred Mysteries at Eleusis. There came a time when the worship of the gods of Olympus did not satisfy the longings of the Greeks for some assurance that the soul was immortal and that there {56} was a life after the death of the body. Demeter grew to be a symbol to the Greeks of the power of the gods to heal and save and to grant immortality. Her story became an allegory of the disappearance of the corn and fruit and flowers in the winter and of their return in the spring, bringing with them gifts to men of hope and life. At the festival of Eleusis, a kind of mystery play on the whole legend was acted. All those who attended the festival were required to prepare for it by a certain ritual of fasting and sacrifice, and it was believed that in the life after death all would be well with those who had taken part in the festival with pure hearts and pure hands. The greatest religious influence in Greece was probably that of the Oracle. This was the belief that at certain shrines specially sacred to certain gods, the worshipper could receive answers to questions put to the god. In very early times signs seen in the world of nature were held to have special meanings: the rustling of leaves in the oak-tree, the flight of birds, thunder and lightning, eclipses of both the sun and moon or earthquakes. It is easy to understand how this belief arose. A man, perplexed and troubled by some important decision he had to make, would leave the city with its bustle and noise, and go out into the country where he could think out his difficulty alone and undisturbed. Perhaps he would sit under a tree, and as he sat and thought, the rustling of the leaves in the breeze would soothe his troubled mind and slowly his duty would become clear to him, and it would seem to {57} him that his questions were answered. Looking up to the sky he would give thanks to Zeus for thus inspiring him with understanding. On his return home he would speak of how he had heard the voice of Zeus speaking to him in the rustling of the leaves, and so the place would gradually become associated with Zeus, and others would go there and seek answers to their difficulties, hoping to meet with the same experience, until at last the spot would become sacred and a shrine would be built there, and it would at length become known from far and near as an Oracle. Plato said of these beginnings of the oracles that "for the men of that time, since they were not so wise as ye are nowadays, it was enough in their simplicity to listen to oak or rock, if only these told them true." Other places would in the same way become associated with other gods, until seeking answers at Oracles became a well-established custom in Greece.