The purpose of this paper is to explore the relationship between W.B. Yeats's obsession with mysticism and his nationalism in his early years (1885-1895). My basic argument is that he knocked at the door of mysticism to find a metaphysical symbol with which he could unify politically, religiously, and culturally divided Ireland. In fact, Yeat's turn to mysticism in his early years attracts many scholars's attentions. But a reading of many studies on this topic leads us to believe that Yeats studied mysticism for other purposes. Elizabeth Cullingford and Richard Ellmann argue that Yeats's preoccupation with mysticism was his antipathy to materialism which was prevalent due to the Industrial Revolution. Seamus Dean explains Yeats's interest in mystical and occult traditions as his efforts to establish an Irish cultural identity. Denis Donoghue maintains that Yeats wanted to separate Irishness from Englishness by dedicating himself to the study of mysticism. In addition to these purposes, I believe, one of Yeats's political agenda was to unify various cultural, religious, and political forces of Ireland before the turn of the century. Yeats firmly believed that the identity of the Irish should be based upon intellectual life and spiritual principles which could solve and transcend the cultual, religious, and political discords of Ireland. The spiritual creeds Yeats was looking for should be founded on the common Irish spirit which could appeal to the Irish whether they were Anglo or Gaelic, Protestants or Catholics, or Unionists or Separatists. In other words, spiritual principles should not be confined to one church. In this sense, Yeats’s choice of Indian thought and occultism is suitable because they have universal appeal. Yeats believed that Indian thought would provide Ireland with the common spiritual tradition which predated both Catholicism and Protestantism. Furthermore, the religious concepts of pantheism and mysticism were the very ideas Yeats needed to bring the conflicting religious and political parties into perfect harmony and balance. Namely, Yeats tried to find a metaphysical model for the unity of Catholics and Protestants through the mystical union.