axiological vs underlying

axiological

adj
  • Of or relating to values themselves. 

  • Of or relating to value theory, the philosophical field of axiology. 

underlying

adj
  • basic or fundamental 

  • implicit 

  • lying underneath 

  • We dug down to the underlying rock. 

noun
  • The entity from whose performance a derivative derives its value. 

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