inflexibleness vs vagary

inflexibleness

noun
  • Obstinacy of will or temper; firmness of purpose that will not yield to importunity or persuasion; unbending pertinacity. 

  • The quality or state of being inflexible 

vagary

noun
  • An impulsive or illogical desire; a caprice or whim. 

  • Something vague. 

  • An erratic, unpredictable occurrence or action. 

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