In a recent book L. P. Wilkinson has said, ‘The chief obstacle to appreciation of the Georgics has been its ostensible genre: it was deceptive and has abundantly deceived. This is no more a didactic poem than Ovid's Ars Amatoria: it simply masquerades as such.’ Throughout the Georgics, however, Vergil explicitly identifies his work as a didactic poem, both by use of didactic convention and through many specific references to the works of earlier didactic poets. Why, then, does Wilkinson reject Vergil's own definition of his work? What is it that makes readers of the Georgics so reluctant to classify it as a didactic poem? Part of the problem, I believe, has to do with the genre itself. Since this literary type is not popular with modern readers, its methods and objectives are not well understood. I will therefore begin this essay with a discussion of didactic convention and of the assumptions that underlie its use. The linguistic structure of didactic poetry provides the poet with an unusual degree of authority and autonomy but it also involves him in certain difficulties. The seriousness of these difficulties is already apparent in Lucretius' De Rerum Natura, a work which profoundly influenced Vergil's development as a poet. In the second part of the paper I will examine Vergil's use of didactic language in the Georgics, placing particular emphasis on the poet's narrative or rhetorical stance. There I hope to show that Vergil makes new demands on this literary genre, for he uses didactic convention as a means for examining and calling into question the fundamental assumptions on which all didactic poetry is based.