 Hume thinks that countries can affect each other's progress. For instance, competition can spur greater progress, and isolation can cause a country to stall (64–5).  On the other hand, countries can intimidate each other into inactivity (76).  Hume also asserts that the arts and sciences cannot progress indefinitely in a single country.  Once they reach a certain height, members of the next generation are too intimidated by their predecessors to strike out on their own (75–76). 