Jefferson accepted a race-based view of human capacities, claiming that Africans were inferior in imagination and intellect.  Casting doubt on Wheatley’s authorship, he nonetheless used what he saw as the weakness of her book to argue that “blacks” had produced “no poetry”:

Misery is often the parent of the most affecting touches in poetry.—Among the blacks is misery enough, God knows, but no poetry. Love is the peculiar œstrum of the poet. Their love is ardent, but it kindles the senses only, not the imagination. Religion indeed has produced a Phyllis Whately [sic]; but it could not produce a poet. The compositions published under her name are below the dignity of criticism.

Boston Public Library, Rare Books & Manuscripts