The first Parthenon sculptures arrived in London in 1802. Initial remarks about them were few, far between, and inconsequential. It was a different matter when in 1806 Richard Payne Knight pronounced a judgment upon them. A wealthy British connoisseur and a member of the Society of Dilettanti, Knight judged the sculptures – by then known as the Elgin Marbles – as aesthetically worthless. He would repeat in years to come that he had “looked over” the marbles and arrived at the same conclusion, a conclusion that stalled Lord Elgin’s efforts to sell the marbles to the British Government. This talk will consider two related questions: why did Knight consider a quick visual examination of the marbles sufficient for estimating their value, and why was his judgment influential? The answers are to be sought in connoisseurial practices and the kind of judgment they were understood to develop, and the ways in which such judgments circulated in early nineteenth-century London. Rather than taking connoisseurial authority as an automatic attribute of social or institutional positions, I examine how such authority was produced in situations that can be delineated and described in their specificities.