Marxism vs conservatism

Marxism

noun
  • The socialist and communist theory of the followers of Karl Marx and Friedrich Engels; a radical, revolutionary political philosophy that aims to capture state power, introduce a dictatorship of the proletariat, and then progress to communism. 

  • The socialist and communist philosophy and political program founded by Karl Marx and Friedrich Engels. 

conservatism

noun
  • A political philosophy that advocates traditional values. 

  • A risk-averse attitude or approach. 

How often have the words Marxism and conservatism occurred in a corpus of books? (source: Google Ngram Viewer )