무너지는 탑, 깊은 샘이나 분수, 넘을 수 없는 분지방의 상징은 메터링 크에게 만큼 예이츠에 해당되며, 사실 전세대에 해당된다. 따라서 이 논문은 예이츠와 메터링크의 상징의 동일성이나 차별성에 주목하는데, 상징의 구상과 사용을 보려고 한 다. 이들은 자신들의 글에서 비슷한 개념을 설명한다. 문학은 본질적으로 상징적이다. 그들은 상징과 알레고리를 구별하는데, 상징은 단순한 추상적 개념의 이미지는 아니 며, 상징은 이성 너머에 뿌리가 있고, 신성한 본질이 있다. 예이츠의 􋺷바일의 스트랜드에서􋺸와 메터링크의 􋺷탱토질의 죽음􋺸과의 비교는 19세기 말의 개념들에서 나타나는 “극적 상징주의”의 특별한 형태를 노출시킬 것이다. 메터링크는 작가란 신성한 상징을 피동적으로 받는 사람이라고까지 믿었던데 반해서 예이츠는 작가의 창조적 힘을 믿었 다. 이점이 두 작가가 다른 기법을 선택하게 만들었던 것이다.

Mysticism was Yeats's lifelong concern and became the center of his work. He believed that mysticism can explain the truth of death, rebirth, the cycle of the universe. By founding his playwriting principles on mysticism, he revived Druidic belief, which had been formed mostly from Irish legends, lore, Celtic mysteries, his reading on Druidism ever since early childhood in Sligo. Yeats thought that a poet must be a mystic and that symbolism is the mystic's aptitude. To treat mystical themes, he needed to make things remote from reality by using symbols, but because of symbolic and mystical content some critics insist he founded his drama based on Noh plays. Even though he thought Noh is an ideal form of drama, it does not mean his drama is an extension of Noh plays. Symbols and 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 he had already learned from Celtic mysticism. The Shadowy Waters is an extremely mysterious story showing visionary experiences of Druidic otherworldliness. In this play, Forgael is following certain birds which are the souls of the dead in search of love. The ghost lovers in The Dreaming of the Bones have been dreaming of fulfilling their love since they died seven hundred years ago, but they can not achieve their dream because of the sin committed 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 shows the same belief in Purgatory, where the dead can not free themselves from purgation due to the consequences of transgressions. In all of the three plays Yeats demonstrates Druidic doctrine that the dead exist and dream in the eternal cycle of birth.