Inspiration and craft offer contrasting models of the poet's activity, which also reflect on the nature and function of poetry itself. Ancient literary criticism treats poetry as a technē and analyzes it from that point of view, but the idea of inspiration is indissolubly linked with poetry through the figure of the Muse. Invoked by poets from Homer onwards, the Muse is both a guarantor of poetic authority and an emblem of everything that is outside the poet's control in the production of a poem. In this chapter I discuss the issues of authorship, authority, and value implied by the imagery of inspiration, and the question of how these relate to the making of a poem. The key text is Plato's Ion in which these issues were first, and most influentially, explored.