inflexibleness vs notion

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 

notion

noun
  • Inclination; intention; disposition. 

  • Mental apprehension of whatever may be known, thought, or imagined; idea, concept. 

  • A sentiment; an opinion. 

  • An invention; an ingenious device; a knickknack. 

  • Any small article used in sewing and haberdashery, either for attachment to garments or as a tool, such as a button, zipper, or thimble. 

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