Mercantilism
Read this article about the many components of mercantilism. Since mercantilism was less a school of thought than a collection of policies, this piece does an excellent job explaining the underlying economic thinking of the time and how it created those policies.
Policies
European economists between 1500 and 1750 are, today, generally considered mercantilists. However, these economists did not see themselves as contributing to a single economic ideology. Rather, its adherents embraced, in various degrees, parts of a set of commonly held theoretical beliefs or tendencies that were best suited to the needs of a particular time and state.
Mercantilism developed at a time when the European economy was in transition. Isolated feudal estates were being replaced by centralized nation-states as the focus of power. This led to frequent military conflicts between nation-states whose governments supported strong military forces. These forces were no longer temporary armies raised to address a specific threat, but were full-time professional forces.
During this period technological changes in shipping and the growth of urban centers led to a rapid increase in international trade.