The Science Behind The Oracle of Delphi

The Oracle of Delphi was a famous and important center of divination in ancient Greece, located at the sanctuary of Apollo in Delphi, on Mount Parnassus. It was considered the most sacred place in the Greek world and served as a spiritual and religious point of reference for many cities and people seeking wisdom, guidance, or prophecies.

The primary role of the oracle was to provide answers and predictions, often through the Pythia, a priestess chosen from among virgins of local aristocratic families, who would enter a trance-like state and relay messages purportedly from the god Apollo. Those seeking guidance, whether individuals, groups, or entire city-states, would pose questions to the Pythia, who would respond with phrases that were often ambiguous or metaphorical. These responses would then be interpreted by the temple priests to offer a clearer understanding of the divine message, such as geographic directions on where to establish new colonies, prevent famines, and so on.

Yet, behind the mystical facade of prophecy, there were more earthly mechanisms at play. Firstly, the realization that her ability to predict the future partially stemmed from the numerous questions asked by visitors and the deliberately ambiguous nature of the Pythia's responses. But beyond psychology, a second field of study explains what was really happening during these sessions—geology.

Several studies have suggested that the prophetic powers were induced by hydrocarbon vapors, specifically ethylene (combined with methane and carbon dioxide). These vapors would rise from rock fractures at the intersections of the fault lines in that area of Greece, causing neurotoxic effects, including trance and delirium. In short, the Pythia was perpetually high, leading to her cryptic and incomprehensible speech. Supporting this theory, traces of gas have been found in the soil and underground water.