This thesis explores the nature of creativity in the poetic vision of Percy Bysshe Shelley. "Poetic vision" is chosen for its complex connotations, which include creative imaginings, dreams and intimations of futurity. I examine questions that Shelley raises concerning perception, existence and the fabric of reality. To develop a conceptual framework that has an ontological basis, I draw on the theories of two twentieth-century non-dualist thinkers: David Bohm, who combines science, philosophy and art, and the existential thought of Martin Heidegger. I also investigate ways in which literary expression and life become interwoven and suggest that this reciprocity is explicable through a dynamically creative vision of existence. In Chapter One Shelley's reflections on the creative capacity of poetic visions to influence states of being, and his holistic apprehension of existence in On Life, provide the thesis with a conceptual paradigm which is in contradistinction to the Cartesian schism between mind and matter. A Defence of Poetry is contrasted with Peacock's The Four Ages of Poetry to show that the contention between the two writers' visions springs from questions relating to being. Shelley's declaration that the poetic impulse is central to life is examined in the light of Heidegger’s notion of the poetic as disclosing being and Bohm's quantum concepts of creativity. In Chapter Two Alastor is interpreted as a poem which raises questions about existence and I provide a counter-approach to critical positions of scepticism. Heidegger's concepts of "Being- in-the-world" and "Being-towards-death" provide the basis for an existential analysis of die Poet’s impassioned quest. A comparison between the Poet's dream of his feminine counterpart and Shelley's own vision of his ideal beloved reveals connections between artistic vision and human experience. In Chapter Three on Laon and Cythna. poetic vision is shown to operate from a metaphysical basis of thought, passion, and the human will to enact a radical transformation in consciousness. The poem's investigation of freedom is linked to Heidegger's concept of being absorbed in the "they." Chapter Four continues my extended reading of Laon and Cythna. Shelley's notion of creativity collapses the demarcations between imaginative vision and the physical world. Here his view of reality is contrasted with the psychological investigations of Jean Piaget. The poem’s vision of human empowerment is compared with Peacock's fatahsm in Ahrimanes. Chapter Five investigates challenges to Shelley's optimism. Julian and Maddalo is the major poem interpreted in a chapter v*ere the keynote is the contention between theories about the nature of reality and their validity to human life. Shelley's anxiety about communicating visions of despair is analyzed with regard to the Maniac's tragic predicament. Chapter Six interprets Prometheus Unbound as a dramatic engagement with the spiritual, imaginative, emotional and sensuous planes of being. Existence is seen to be poised on a mobile nexus of thought and emotions. Asia has a dynamic role and, through consideration of her journey with Panthea to Demogorgon, I examine Shelley's complex negotiation between free will and determinism. Spinoza's monism is discussed in relation to "Love's Philosophy. In Chapter Seven on Hellas, "Thought", "Passion", "Will", "Reason" and the "Imagination” are shown to have creative powers which determine futurity. Questions about the structure of reality are explored in the drama's dynamic interchange between the magician-like Ahasuerus and the Turkish tyrant Mahmud. Dreams are given significance as avenues of perception to realms beyond conscious experience and in relation to unfolding the future. Finally, in Chapter Eight Shelley's ideas about poetic creativity are explored through his poems to 'Jane Williams. Whilst composing these lyrics Shelley used the figure of Rousseau, in the Triumph of Life, to suggest a reciprocity between art and life. I examine the similarities between Rousseau's fictional creation of Julie in La Nouvelle Hélose and his subsequent love for Sophie d'Houdetot. Shelley's lyrics to Jane Williams communicate desire at different levels of conscious awareness, from trance-like mesmerism to overt invitation.