The correspondence presented in this fourth volume of Wesley's letters casts light on the growth of his movement, documenting (for example) the emergence of connection-wide financial campaigns and continuing debates over the desire of lay preachers for ordination. It covers the decisive split between the Wesleyan and Calvinist wings of Methodism, including the ways in which Charles Wesley drew closer to his brother through these developments. The volume includes over 100 items not found in previous editions of Wesley's letters.