Augustine has had a large influence on the development of western theology, and nowhere is this more obvious that in Martin Luther's understanding of God, humankind and grace. Yet at the same time there are also significant differences in the two churchmen's thought. Sometimes these differences are subtle, such as their views of the state; other times they are not so subtle, such as their positions on free will or their praise of philosophy and its usefulness in sounding the depth of Christianity. In order to best explain these varying views, one must look at Augustine's and Luther's diverging opinions of man's nature where one will see that the dissimilarities are best understood in light of Luther's pessimistic view of humanity.