As a sociologist, Nisbet is using the term “capitalism” to refer to the historical system called capitalism. As economists, we use tend to use the “free market economy” or “unhampered market economy” as a synonym with “capitalism.” Nisbet is a champion of liberty and order, an order brought about without the state..
David Gordon lists Nisbet’s book as one of the 100 most important works on liberty:
http://mises.org/daily/1830
Here are a few appreciations of Nisbet:
http://www.garynorth.com/public/10962.cfm
http://www.lewrockwell.com/2001/05/gary-north/nisbet-rushdoony-and-rothbard/
http://antiwar.com/stromberg/?articleid=3371