This paper is an attempt to discuss Yeats's Four Faculties and symbolic approach in A Vision. He tried to search for how to make many symbols and images drawn in his poetry into one principle and theory and put it together in A Vision. He used Four Principles to explain the cycle of reincarnation while he made use of Four Faculties to show the stream of consciousness. He insists that we have many spiritual conflicts and pains. However we can solve this conflict and confrontation through the course of Four Faculties. He elaborately explains that this kind of stream of consciousness divides in Four Faculties and this travels on the phases of the moon in A Vision. These Four Faculties are Will, Mask, Creative Mind, and Body of Fate. Will is understood that what's the feeling has not become desire because there is no object to desire. Mask is understood the image of what we wish to become. Creative Mind meant intellect. And Body of fate is understood the physical and mental environment, the changing human body, and the stream of phenomena as this affects a particular individual, all that is forced upon us from without. Four Faculties movement means that the change of relative force in each pair of psychical function unites with the principle symbol of the 28 phases of moon. In a sense though this symbol is actually his own volition, this also has a beauty and mighty force. Transformation of the 28 phases of moon relates to cross over from the Primary to the Antithetical. Phase 15 and phase 1 emblematized the unity of Will and Creative Mind not moving and fixing. In phase 15, the feeling of introversion easily changes into the thought of introversion through material that is subjective image, or archetypical image. However in phase 1, the intuition of extroversion changes into the sensation of extroversion through the focus from without. These two phases make reconciliation rather than conflict. In conclusion, through the unity of subjective image, Unity with God, Unity with Nature, we experience the moment of tranquility in which reincarnation presents itself outside of cycle of phases. The synthesis from without opposed to the unity of image in the center of the Antithetical. Therefore Yeats shows the method of Unity with Nature, Unity with God, and Unity of Being in A Vision. However he insists the ideas of Unity of Being in his poems.