Mysticism was Yeats’s lifelong concern and became the center of his work. Hebelieved that mysticism can explain the truth of death, rebirth, the cycle of theuniverse. By founding his playwriting principles on mysticism, he revived Druidicbelief, which had been formed mostly from Irish legends, lore, Celtic mysteries, hisreading on Druidism ever since early childhood in Sligo.
Yeats thought that a poet must be a mystic and that symbolism is the mystic’saptitude. To treat mystical themes, he needed to make things remote from reality byusing symbols, but because of symbolic and mystical content some critics insist hefounded his drama based on Noh plays. Even though he thought Noh is an idealform of drama, it does not mean his drama is an extension of Noh plays. Symbolsand the supernatural content were his solid principles long before he saw Noh plays.Furthermore, the similar themes in both Noh plays and Yeats’s are something hehad already learned from Celtic mysticism.
The Shadowy Waters is an extremely mysterious story showing visionaryexperiences of Druidic otherworldliness. In this play, Forgael is following certainbirds which are the souls of the dead in search of love. The ghost lovers in TheDreaming of the Bones have been dreaming of fulfilling their love since they diedseven hundred years ago, but they can not achieve their dream because of the sincommitted during life. This connotes something about Yeats’s belief in purgation.He believed the dead have to live anew until the purgation is finished. He showsthe same belief in Purgatory, where the dead can not free themselves frompurgation due to the consequences of transgressions. In all of the three plays Yeatsdemonstrates Druidic doctrine that the dead exist and dream in the eternal cycle ofbirth.