The nine cantos of Queen Mab (M&E 265–424) open in unlikely fashion for a poem that was to become, as G. B. Shaw was later told by one of them, ‘the Chartists’ Bible’. Its intent, though, is to revive a discourse uniting scientific and political scepticism, one associated with the materialism of Locke and the philosophes and traditionally thought inimical to the Romantic imagination. The opening of Shelley's major début dispels all that:

From the start the poem challenges us to find alluring the dissemination of individual self-consciousness. Initial echoes of the earliest Greek literature, Hesiod's mythology and Homer's epithets, mingle with those of early English Romanticism. Shelley pointedly resituates and develops the opening of Thalaba the Destroyer (1801), a revolutionary romance penned by the sometime radical Robert Southey, now turned Tory, whom Shelley had met and argued with at length in December 1811, the year before he wrote Queen Mab. Shelley's allusive recovery of literary and political innocence prepares for the image of a sleeping girl, Ianthe, who arrests the chariot of the fairy queen, Mab, in her celestial flight. Photic and kinetic fantasy then unite in this figure of Queen Mab, who rewards the virtuous Ianthe by transporting her soul (‘The perfect semblance of its bodily frame’) to the vantage point of her palace. Its eminence affords astronomical and chronological insights, improving this time on Volney's panoramic Les Ruines, ou méditations sur les révolutions des empires (1791), which had fuelled the scepticism of the last generation of radicals. Ianthe is told the laws of universal history and the history of the universe; each is as observant of the other's causal patterns as Ianthe's soul is reproductive of her body's shape. The heady mixture of different visionary idioms elaborates the poem's materialism, its version of an animism common to French and English radical thinkers from philosophes like Holbach to Dissenting theorists like Erasmus Darwin: