obtuseness vs refinement

obtuseness

noun
  • The quality of being obtuse. 

  • Something that is obtuse. 

refinement

noun
  • A fine or subtle distinction. 

  • The act, or the result of refining; the removal of impurities, or a purified material 

  • High-class style; cultivation. 

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