The most renowned oracles were those of Delphos, Dodona, Trophonius, Jupiter Hammon, and the Clarian Apollo. Some have attributed the oracles of Dodona to oaks, others to pigeons. The opinion of those pigeon-prophetesses was introduced by the equivocation of a Thessalian word, which signified both a pigeon and a woman; and gave room to the fable, that two pigeons having taken wing from Thebes, one of them fled into Lybia, where it occasioned the establishing of the oracle of Jupiter Hammon; and the other, having stopped in the oaks of the forest of Dodona, informed the inhabitants of the neighbouring parts, that it was Jupiter's intention there should be an oracle in that place. Herodotus has thus explained the fable: there were formerly two Priestesses of Thebes, who were carried off by Phenecian merchants. She that was sold into Greece, settled in the forest of Dodona, where great numbers of the ancient inhabitants of Greece went to gather acorns. She there erected a little chapel at the foot of an oak, in honour of the same Jupiter, whose priestess she had been; and here it was this ancient oracle was established, which in after times became so famous. The manner of delivering the oracles of Dodona was very singular. There were a great number of kettles suspended from trees near a copper statue, which was also suspended with a hunch of rods in its hand. When the wind happened to put it in motion, it struck the first kettle, which communicating its motion to the next, all of them tingled, and produced a certain sound which continued for a long time; after which the oracle spoke.
This oracle, which was in the desert, in the midst of the burning sands of Africa, declared to Alexander that Jupiter was his father. After several questions, having asked if the death of his father was suddenly revenged, the oracle answered, that the death of Philip was revenged, but that the father of Alexander was immortal. This oracle gave occasion to Lucan to put great sentiments in the mouth of Cato. After the battle of Pharsalia, when Cesar began to be master of the world. Labrenus said to Cato: "As we have now so good an opportunity of consulting so celebrated an oracle, let us know from it how to regulate our conduct during this war. The gods will not declare themselves more willingly for any one than Cato. You have always been befriended by the gods, and may therefore have the confidence to converse with Jupiter. Inform yourselves of the destiny of the tyrant and the fate of our country; whether we are to preserve our liberty, or to lose the fruit of the war; and you may learn too what that virtue is to which you have been elevated, and what its reward."