What could be the relevance of sixteenth century Netherlandish art theory to the interpretation of Bruegel’s paintings? To many readers this will seem a puzzling question, since art theoretical matters have almost entirely been neglected in the study of sixteenth century Netherlandish art. Sometimes, it seems, they are not even felt to exist. But there was at least one lively theoretical controversy in Bruegel’s time that deserves to be brought to the fore rather more sharply than it has so far. The two main documents for the controversy raise an issue of considerable significance for the study of his work as a whole; and they happen to highlight some of the chief interpretive problems that occur when one considers the meaning of his paintings and prints. But I will not begin with theory and end with the problem of allusion; the two problems are too complexly interwoven to do that. They also point to several further desiderata for future research in the field.