passivity vs stoicism

passivity

noun
  • The state of being passive. 

  • A lack of initiative. 

  • Submissiveness. 

stoicism

noun
  • A real or pretended indifference to pleasure or pain; insensibility; impassiveness. 

  • A school of philosophy popularized during the Roman Empire that emphasized reason as a means of understanding the natural state of things, or logos, and as a means of freeing oneself from emotional distress. 

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