One key trait of the gods of Ancient and Classical Greece was that they were never alone. Qu'est-ce qu'un dieu grec ? thus strives to define what the Greek god would be like in all of his « states », if we may use that term — the god of mythological tales, as well as the one to whom religious rites and practices were dedicated. To achieve this, the author drew from all available sources such as Homer, Hesiod, the Homeric Hymns, Greek tragedies, as well as archaeology, and inscriptions or images on urns.
In this work, the Greek god is perceived as a « power » integrated into various forms of « pantheons », and is thus approached in his relation to space, time, human communities, or in the forms in which he appears to humankind and can be represented.
Although based upon major studies by historians of Greek religion, this work is original in that it attempts to unmask certain a few misconceptions, and to share some convictions about Greek gods which are a part of our common heritage.

Greek history professor Pierre Sineux of Université de Caen is an expert in cults and healing gods of the ancient Greek world.