degrade vs heighten

degrade

verb
  • To lower in value or social position. 

  • To reduce in altitude or magnitude, as hills and mountains; to wear down. 

  • To reduce in quality or purity. 

heighten

verb
  • To make high; to raise higher; to elevate. 

  • To advance, increase, augment, make larger, more intense, stronger etc. 

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