The dissertation investigates the status of the dream-vision in the poetry of John Lydgate, James I of Scotland, Charles of Orleans, Robert Henryson, William Dunbar and the anonymous poet of The Court of Sapience through an examination of the poetry in relation to the philosophical, literary and rhetorical traditions which informs it. First, the dissertation traces the evolution of a group of metaphors which link rhetoric, cosmogony and sexuality from early hexaemeral commentaries on the first chapter of Genesis through the Latin visionary poems of Bernardus Silvestris and Alan of Lille in the twelfth century. It then examines manuscript evidence to show the extent and nature of the circulation of Bernardus and Alan in fifteenth-century England. By the fifteenth century, as the dissertation demonstrates, the dream-vision had become the locus of a complex deployment of self-reflexive rhetorical and cosmogonic metaphors which rendered the dream a synecdochal site of an intertextually mediated 'allegory of reading'; that is, the dream and dream-vision poetry had come to represent a way of reading the poetic tradition. The dissertation then proceeds to a series of individual readings of the dream-vision poems of Lydgate and his followers, showing the extent to which they allegorize poetic self-reflexivity. By the fifteenth century the dream-vision had developed into two, often overlapping traditions: the philosophical and the amorous. The fifteenth-century poets under consideration here merged the two traditions through a metaphorization, drawing on Alan of Lille, of rhetoric as eroticism. At the same time they continued to valorize rhetoric as analogous to God's work, drawing on both Alan and Bernardus.