Yeats argues that symbolism is the heart of poetry. The use of poetic images and sounds evoke subtle, complex emotions and has an ability to embody indistinct feelings which “can help unlock the power of unconscious associations and spiritual experiences.”
Yeats writes that, “all sounds, all colors, all forms, either because of their preordained energies or because of long association evoke indefinable and yet precise emotions/…call down among us certain disembodied powers, whose footsteps over our heart we call emotions”, and when all these are in accordance with one another in a kind of mysterious, yet systematic formal unity, those separate and distinct emotions, once synthesized, demonstrate the consubstantiality of our existence in the spectra of human emotion and reality–this is what is meant by a philosophy of poetry in the doctrine of symbolism, or as Yeats puts it, “the continuous indefinable symbolism which is the substance of all style”, all works of art, and the “making and unmaking of mankind”. What he is describing here is nothing new—it is, tersely phrased, the “oneness” connecting us all.
He writes “an emotion does not exist”, or at least is not perceptible, “till it has found its expression”—this is the moment of release. The power of poetry lives in the creative subconscious, in moments of deep solitary reflection or periods of madness, when the soul moves along symbols and unfolds them before us impulsively, revealing the depths of the human spirit.
Man and his symbols—the poet and his art—are nothing but the sum total of emotions—how we make sense of the world through contemplative thought and bring about creative expression. What I gathered from Yeats words was that with poetry, under the doctrine of symbolism, it’s all about conjoining an abstract idea with a concrete image (the intellectual with the emotional) where analysis may be objectively drawn, but ultimately is deeply subjective, though the nature of its experience is universally felt.