These are the questions which Luther struggles to address. Luther concludes that a soldier must take his faith seriously enough to question authority. He does however say, that at the end of the day when one has struggled with such questions, our trust and our confidence are not in our faculties of reason but in the One who has given us these faculties. It is precisely for this reason that Luther tells Christians that they ought to support schools and educate their children. It ought to be a matter of great honor and satisfaction for you to see your son an angel in the empire and an apostle of the emperor, a cornerstone and bulwark of temporal peace on earth, knowing for a certainty that God so regards it and that it is really true.
Faith ought to impel the believer to godly service in society.
If he means that Lutherans or at least the two kingdoms doctrine thinks that academic culture is neutral or that it is neutral about its assumptions about humanity and God, about nature and the cosmos, then I think that I and others have misled Von Dohlen. Reason can accomplish some things, but it can seriously mislead. For this reason Luther says that what we can say about God always has to be said in light of the cross. He merely argues that a Christian lives in the world, the world is good because God created it, and therefore a Christian ought to contribute to the welfare of God's good creation by participating with God in fighting against the forces which threaten to upset good order and peace. Each discipline has its own legitimate epistomology.