selfsameness vs unvariedness

selfsameness

noun
  • The property of two or more appearances of being of the selfsame underlying object; sameness as regards self or identity; identity; identicality. 

unvariedness

noun
  • The quality or characteristic of being unvaried. 

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