The phantasmal quality of Percy Bysshe Shelley's poetic language probes and interrogates the boundary between the living and the dead while exposing the interconnectedness of the sensory and the mental. His skylark, “Like an unbodied joy,” is an unseen bird which is really a song, its bodily significance usurped by its “profuse strains of unpremeditated art”; his west wind is an “unseen presence” which drives leaves, “like ghosts from an enchanter fleeing”; in “Mont Blanc” the speaker seeks “among the shadows that pass by / Ghosts of all things that are, some shade of thee, / Some phantom, some faint image.” As Susan Wolfson observes, “Shelley's visionary poetics—from Hymn to Intellectual Beauty, to Ode to the West Wind and To a Sky-lark, to The Triumph of Life—know the force of negating the known into the apparition.” Earlier generations of Romanticists recognized, analyzed, and indeed privileged the supernatural in Shelley's poetry, while in recent decades, political, historical, and scientific understandings of Shelley have achieved ascendency. Informed by the trends in recent scholarship and literary theory, without minimizing the political and scientific, we ought now to re-examine the “supernatural” in Shelley, because ghosts and spirits are ubiquitous in his writing, nor are these phantoms mere decorative motifs. Rather, Shelley explores the invisible in order to express a complex and nuanced spirituality consistent with his skepticism and scientific learning; the natural is telescoped through the supernatural to challenge distinctions between the two. Furthermore, Shelley's dialogism softens the monism of his ubiquitous “One,” creating a polychromatic rather than a monochromatic visionary poetics which achieves a polyphony of spiritual potentiality symbolized by a plethora of ghosts and spirits.

Shelley was a poet unusually susceptible to influence by and admiration for other writers: some of his crucial literary relationships, with Plato, Milton, Wordsworth, and Byron, have received extensive critical attention. However, the larger question of why and how literary influence is so central to Shelley also requires study.