[A] beautiful and ineffectual angel [Shelley], beating in the void his luminous wings in vain.

Matthew Arnold’s phrase comes from his critical essay on Percy Bysshe Shelley, written in the Victorian period when Arnold was arguing for poetry’s “high seriousness” and for a moral and intellectual steadiness in great writers. In assessing Shelley’s genius, Arnold praises the poet’s radiance and idealism but faults him for lacking what Arnold calls “substance” and “power” in the practical, ethical, and intellectual sense. The image of an “angel” conveys Shelley’s purity and visionary aspiration; “ineffectual” reflects Arnold’s view that Shelley’s poetry, for all its beauty, does not achieve the kind of grounded, culturally formative force Arnold admired in poets like Shakespeare, Dante, or Goethe.

The metaphor casts Shelley as a luminous, otherworldly being whose efforts cannot gain purchase on reality: he “beats” his wings, but only in a “void,” and therefore “in vain.” Arnold is not denying Shelley’s brilliance; he is defining it as brilliance without efficacy—splendor without the weight of mature thought, disciplined form, or moral authority. The line has become a shorthand for a certain Romantic temperament: intensely idealistic, emotionally and imaginatively powerful, yet politically or philosophically unanchored. It also reveals Arnold’s own critical program, which values poetry not merely as rapture but as a stabilizing, civilizing force in modern life.