The metrical sections of the Old English Boethius have traditionally been regarded as little more than mechanical versifications of the relevant portions of the entirely prose version. This article, however, argues that The Metres of Boethius present an ambitious psychological discourse. The adaptations made during the versification process allow the poet to expand upon the prose source and place greater emphasis on the care of the inner mind. The model of the mind in the Metres owes much to the tradition of vernacular poetry, in which the mind is a separate, wilful part of the self, in need of restraint. Yet the Metres are also indebted to the tradition of their ultimate Latin source, in which the mind has the ability and, indeed, the responsibility, to monitor its own inner depths. This article demonstrates that the Metres-poet engages with both traditions, crafting a strikingly original model of the mind.