encourage vs preclude

encourage

verb
  • To mentally support; to motivate, give courage, hope or spirit. 

  • To spur on, strongly recommend. 

  • To foster, give help or patronage 

preclude

verb
  • Remove the possibility of; rule out; prevent or exclude; to make impossible. 

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