Presents the first masterpiece of Scottish Common Sense philosophy. This two-volume treatise is important for its wide range of insights about the nature of the human mind, the foundations of morals, and the relationship between morality and religion. In order to understand the Enlightenment in Scotland, Turnbull's work must be put next to that of Francis Hutcheson. In the second volume Turnbull presents arguments for the existence of God and for God's infinite perfection. The underlying notion here is God's moral government of the world, a government that is particularly at work in the allotment of recompense for our good and evil deeds. The Liberty Fund edition of The Principles of Moral and Christian Philosophy is the first modern edition of this work.