William Blake’s relationship to competing strains of antiquarianism in the last half of the eighteenth century played a major role in the ways he understood art history. Eighteenth-century British antiquarianism comprised sometimes-overlapping, sometimes-opposing categories of study, and its connotations prove difficult to recover. As a result, contemporary scholars tend to label the kinds of antiquarians who studied classical antiquity ‘connoisseurs’ because they often collected and displayed the things they studied, and because they were just as likely to collect the works of Moderns as they were of the Ancients. The word antiquarian in contemporary scholarship, on the other hand, has generally been reserved for the study of the materials from the ancient British past. At the time, however, the term ‘antiquarian’ as often referred to scholars of classical erudition like Sir William Hamilton as it did to the ‘popular’ antiquarianism of George Vertue or Horace Walpole. British connoisseurship as it was practised by classical antiquarians was commonly associated with a constellation of affinities, including cosmopolitanism, the reverence of classical art, an interest in pagan religions, and some frank and omnivorous appetites, which often found outlet in grand tourism, homosocial club culture, and their attendant sexual liaisons (Brewer, 252–87). By contrast, popular antiquarianism was characterised as more isolated and isolating, its practitioners often minutely preoccupied with ancient British artifacts and architecture, old ballads, and vernacular languages. However, the word antiquarian simply meant, as the OED tells us, ‘One who studies or is fond of antiquities. . . ’ be they British or Roman or, as often was the case, Roman artifacts unearthed from British soil. In this essay, I want to situate the anticlassicism evident in Blake’s late works in terms of a disdain for English connoisseurship as practised by a certain highly visible group of classical antiquarians. While Blake’s attitude towards Hellenism may have shifted over the course of his life, evidence of his dislike for the English practitioners of classical antiquarians can be found throughout his work. Blake came to understand classical and popular antiquarianism as opposing categories, and these categories informed his Protestant renegotiation of the history of art. A deeper understanding of Blake’s relationship to these antiquarian practices of his day offers rich rewards, since it gives a clearer picture of what is at stake in Blake’s poetry about art. In particular, I offer a reading of the Notebook verse ‘If it is True what the Prophets write’, a poem that has had little scholarly attention.