Following a number of recent studies of Jonathan Edwards (1703–58) on the holy spirit that treat a particular aspect of the function of the spirit – for example, in the process of assurance (S. J. Nichol, 2003) or in revival (W. van Vlastuin, 2001; M. A. G. Haykin, 2005) – Robert Caldwell has offered the best attempt so far at a comprehensive overview of the topic. For Caldwell, as his title suggests, the holy spirit is ‘the bond of union’ within the Trinity, between Christ's two natures, between a Christian and Christ, between members of the Church on earth, and in heaven. Sections within the book examine each of these relationships, highlighting the connection between the activity of the immanent Trinity and its economic operations in redemption. For Edwards, the love and union between the persons of the Trinity models the act of creation (and for Edwards, it is continuous creation), the history of the unfolding work of redemption, and believers' participation with the divine essence through and in Christ. This book therefore addresses the Trinitarian foundations of the spirit's work, assays to restore ‘pneumatological balance’ in Reformed Trinitarian theology through its focus on the Second Person, and begins to place Edwards within a long western theological tradition (an issue that needs to be addressed more fully than Caldwell is able to do here). Edwards's views on the holy spirit as the bond of union reveal that his larger theology was broadly Augustinian and stressed a continuity between the immanent and economic Trinities.