This essay addresses an ongoing controversy over whether the mature John Donne embraced Calvinist or Arminian theology by advocating a new middle way. His Holy Sonnets composed around the time of his conversion indeed reflect the fear and trembling of Calvinist belief; striking continuities clearly exist between them and the methods of "experimental predestination" advocated by William Perkins. Perkins used a fearful set of "hammers"—knowledge of God's law, wrath at human sin, and our total helplessness to merit grace or be saved on our own—to humble souls otherwise unable to "achieve" election. Yet as the word "achieve" suggests, his system included hidden elements of voluntarism useful not only personally to Donne but also to his later preaching career. By consistently expanding these elements, especially the role of penitence as a "work" of grace and love rather than of the will, he softened Calvinist orthodoxy without fully embracing Arminianism in both his late Holy Sonnets and sermons.