Bradan Feasa- Celtic CreatureCreature"Salmon of Knowledge"

The Hazels of Segais

At the source of the River Boyne, in the heart of the Otherworld according to Irish tradition, stood the Well of Segais (also called Connla's Well), surrounded by nine hazel trees. These were no ordinary trees: their nuts contained all the knowledge and wisdom of the world. When the hazelnuts fell into the water, they were consumed by a great salmon dwelling in the pool. With each nut the salmon ate, it absorbed more of the world's wisdom, until it had consumed all nine and become the repository of all knowledge. This salmon, called the Bradán Feasa and in some traditions named Fintan, had swum in the pool since the beginning of the world. A prophecy declared that whoever first ate its flesh would gain all the wisdom it contained.

The druid-poet Finnegas devoted seven years of his life to catching the Bradán Feasa, sitting by the pool of Fec on the River Boyne, watching and waiting. Finnegas believed the prophecy applied to him, for his name contained "fionn" (meaning fair or bright), and it had been foretold that one named Fionn would eat the salmon and gain its wisdom.

Fionn's Thumb of Knowledge

Finnegas finally caught the salmon and set the young Demne, a boy who had come to study under him, to cook it over a fire, strictly instructing him not to eat any of the fish. As the boy tended the cooking salmon, a blister rose on its skin. Demne pressed his thumb against the blister to push it down, and the hot fat burned him. Instinctively, he put his burned thumb into his mouth to ease the pain. In that instant, the wisdom of the salmon passed into him. When Finnegas returned and saw the light of knowledge in the boy's eyes, he understood that the prophecy had been fulfilled, but not for him. He asked the boy his name, and when Demne revealed that he was also called Fionn, Finnegas gave him the rest of the salmon to eat, accepting that the boy was the one the prophecy had foretold.

From that day, the boy was known as Fionn mac Cumhaill. Whenever he needed to access the imbas (prophetic knowledge) the salmon had granted, he placed his thumb between his teeth, and the wisdom would come to him. This gift, known as the "thumb of knowledge" (ordóg an eolais), served Fionn throughout his career as leader of the Fianna, allowing him to perceive hidden truths, foretell danger, and make judgments of preternatural wisdom. The Macgnímartha Fhinn (Boyhood Deeds of Fionn) preserves this tale as the central episode in the young hero's coming of age.