If you're the least bit interested or just a bit curious about the sources of economic thought in society (ours and Europe's) over time I recommend reading the subject article  (essay).

It effectively traces the cyclical nature of political economy between the two types of theory ?? one assuming markets and nature fix all problems (i.e. social darwinian, laissez-faire economy) while the other sees the need for policy and activism (i.e. state regulated and controlled economy)... both in Europe and in the US.  It shows that both types have dominated and then reversed, then re-reversed again.   The author argues that nations which use economic theory that isn't based on the real economy produce extremes which end in economic disaster... either extreme (laissez-faire & Russian style communism).  The real economy is different from the economy of theory where real world conditions and factors are increasingly abstracted to the point of becoming irrational beliefs.. aka quasi religion.

The essay (long.. be prepared for 45 minutes of dedicated reading time) provides highly relevant perspective of economic thought ... applicable to the present state of affairs and how the global economy got where it is today.   The author also shows that the disastrous endings of economic paradigms that don't account for the real economy have in fact been actual or virtual revolutions.  

Basically, if you don't read this essay, you're probably harboring a belief which is based on a recent invocation (past generation or two) of the two paradigms that have cyclically reversed and re-reversed over time... and of course that belief is founded on the dominant economic theory of the time (in which we were educated, infused, &/or experienced).   Putting these in perspective is highly enlightening and educational.   

The author (fyi ...  just so you know it isn't by Krugman or Stieglitz, nor my link to this article come from them).  

Erik S. Reinert is Professor of Development Strategies at Tallinn University of Technology, Estonia, and President of The Other Canon Foundation, Norway. His work on the history of economics and its public mission includes his book How Rich Countries Got Rich and Why Poor Countries Stay Poor (2007) and the forthcoming co-edited volume Thorstein Veblen: Economics for an Age of Crises.