In the Greek temple of Delphi were written the words of an anonymous Greek writer, "KNOW THYSELF."
To know our own strengths and weakness is perhaps one of the hardest bits of knowledge to aquire, but it is certainly one of the most worthwhile. In it lies a good deal of our own happiness - and that of all those around us.
********************************************************************************
Delphi is perhaps best known for the oracle at the sanctuary that was dedicated to Apollo during the classical period. According to Aeschylus in the prologue of the Eumenides, it had origins in prehistoric times and the worship of Gaia. In the last quarter of the 8th century BC there is a steady increase in artifacts found at the settlement site in Delphi, which was a new, post-Mycenaean settlement of the late 9th century. Pottery and bronze work as well as tripod dedications continue in a steady stream, in comparison to Olympia. Neither the range of objects nor the presence of prestigious dedications proves that Delphi was a focus of attention for a wide range of worshippers, but the large quantity of high value goods, found in no other mainland sanctuary, certainly encourages that view.
Apollo spoke through his oracle: the sibyl or priestess of the oracle at Delphi was known as the Pythia; she had to be an older woman of blameless life chosen from among the peasants of the area. She sat on a tripod seat over an opening in the earth. When Apollo slew Python, its body fell into this fissure, according to legend, and fumes arose from its decomposing body. Intoxicated by the vapors, the sibyl would fall into a trance, allowing Apollo to possess her spirit. In this state she prophesied. It has been postulated that a gas high in ethylene, known to produce violent trances, came out of this opening, though this theory remains debatable. While in a trance the Pythia "raved" – probably a form of ecstatic speech – and her ravings were "translated" by the priests of the temple into elegant hexameters. People consulted the Delphic oracle on everything from important matters of public policy to personal affairs. The oracle could not be consulted during the winter months, for this was traditionally the time when Apollo would live among the Hyperboreans. Dionysus would inhabit the temple during his absence.
H.W. Parke writes that the foundation of Delphi and its oracle took place before recorded history and its origins are obscure, but dating to the worship of the Titan, Gaia.
The Oracle exerted considerable influence throughout the Greek world, and she was consulted before all major undertakings: wars, the founding of colonies, and so forth. She also was respected by the semi-Hellenic countries around the Greek world, such as Lydia, Caria, and even Eygpt. The oracle was also known to the early Romans. Rome's seventh and last king, Lucius Tarquinius Superbus, after witnessing a snake near his palace, sent a delegation including two of his sons to consult the oracle.
List of famous orcular statemenets:
http://en.wikipedia.org/wiki/Famous_Oracular_Statements_from_Delphi