This paper examines Augustine's analysis of the possible causes of akrasia and suggests that an implicit two-phased consent process takes place in an akratic decision. This two-phased consent theory revolves around Augustine's theory of the two wills, one carnal and the other spiritual. Without the help of grace, the fallen will dominated by the carnal will can only choose to sin. After exploration of this two-phased consent theory, the paper turns to examine the accusation made by Julian of Eclanum, a fifth-century Pelagian, and J. Van Oort, a contemporary Augustinian scholar, that Augustine's doctrine of the two wills and concupiscence led the Church into a Manichaean position. The paper concludes that this accusation fails to hold up, especially when one considers the more nuanced view on the human body and concupiscence in Augustine's later works.