ax to grind vs mania

ax to grind

noun
  • A proposition or point of view to advocate, especially motivated by self-interest. 

  • A grudge or grievance, with implications of confrontation. 

mania

noun
  • Excessive or unreasonable desire; insane passion affecting one or many people; fanaticism. 

  • Dotcom mania was slow in coming to higher education, but now it has the venerable industry firmly in its grip. Since the launch early last year of Udacity and Coursera, two Silicon Valley start-ups offering free education through MOOCs, massive open online courses, the ivory towers of academia have been shaken to their foundations. 

  • The state of abnormally elevated or irritable mood, arousal, and/or energy levels. 

  • Violent derangement of mind; madness; insanity. 

  • 2013-07-20, “The attack of the MOOCs”, in The Economist, volume 408, number 8845 

How often have the words ax to grind and mania occurred in a corpus of books? (source: Google Ngram Viewer )