A major theme of this enquiry so far has been the relationship between knowledge, critical reflection and power. As we have seen, it was not only philosophers like Immanuel Kant who reflected on the lengths to which unlimited Enlightenment could be taken, before it began to disrupt, rather than illuminate, the structures of society. In this chapter we confront the issue in the most direct way. We examine the extent to which Enlightenment ideas were used by governments in this period, and what impact if any these ideas had not only on government policy, but also on the nature of government itself. We will see if debates on government intervention in the economy, and in church–state relations as well as much wider ranging controversy on what constituted legitimate government may have prepared the way for the wave of revolutionary movements which accompanied the Enlightenment and which was to culminate in the upheavals in France from 1789 onwards (Chapter 10). We will also try to establish how Enlightenment ideas helped or hindered rulers in their search for international success, and internal stability and prosperity.