In this 17th century treatise, Flavel lays out an extensive biblical and theological account of the human soul. He touches on problems concerning the soul’s immortality, how the soul and the body connect with each other, and the ethical questions that flow out of these problems. Following St. Augustine, he argues that the temporality of the body and the eternality of the soul should naturally press Christians to chase after the eternal only, and forsake carnal pleasure in excess. In general, Flavel’s arguments follow a reinterpretation of Christian tradition through the lens of the then scandalous English Reformed faith.