inflexibleness vs self-control

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 

self-control

noun
  • The ability to control one's desires and impulses; willpower. 

verb
  • To control oneself or itself. 

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