Simon Episcopius was the leading theologian of the early Remonstrant movement. A close friend and admiring pupil of Jacob Arminius, he followed his mentor to a chair in Leiden and was the leading spokesman for the Remonstrants during the Synod of Dort. The Remonstrant Brotherhood increasingly looked to him for direction during the period of exile which followed that synod and, after his return to Amsterdam in 1629, Episcopius' leadership of the movement was uncontested. He produced the sacramental liturgies which the Brotherhood used, as well as founding and directing the Remonstrant seminary. Episcopius taught the later exponents of Remonstrant theology, Stephen Curcellaeus and Philip van Limborch, and his thought became particularly influential in post-Restoration England, deeply marking the theology of, amongst others, John Tillotson. Given Episcopius' significance to the development of Protestant theology during the seventeenth century, and the relative lack of scholarly attention that has been paid to him, Mark Ellis's book is a particularly welcome contribution to the history of doctrine. Ellis expounds Episcopius' views on original sin against the background of Arminius' thought in this area, with the stated aim of demonstrating that, whilst Episcopius does depart from Arminius at certain points, those departures should be seen as legitimate developments of his mentor's hesitations about Reformed theology. In Ellis's view, Episcopius should not be seen (as some scholars have portrayed him) as the man who uprooted Arminian theology from its Reformed heritage and transplanted it into the less healthy soil of early modern rationalism, but rather as a theologian prepared to push Arminius' own conclusions a little further and to carry out a more searching application of humanist textual principles to the business of theological exposition. Ellis introduces his book with a helpful summary of the current scholarship on Episcopius and on Arminian theology more generally. He then offers a historical account of the development of the Remonstrant movement from the time of Arminius, before expounding Arminius' own views on original sin. His presentation of Episcopius' thought is divided into two chapters: the first expounding Episcopius' early views and comparing them with those of Arminius; the second setting out Episcopius' mature theology and contrasting it with his previous insights. It is perhaps regrettable that not all the quotations from non-English sources are translated. However, Ellis's presentation of his subject matter is clear and helpful, enabling the reader to acquire a solid grasp both of the broad shape of Arminius' and Episcopius' theology of original sin, and of the specific points of distinction or development between them. This book makes a significant contribution to the study of Dutch Arminianism, and so (given Arminianism's abiding influence in England in particular) to the history of Protestant theology more generally.