harmful vs promising

harmful

adj
  • of a kind likely to be damaging; injurious 

promising

adj
  • Showing promise, and likely to develop in a desirable fashion. 

  • a promising young apprentice 

  • Encouraging and inspiring confidence. 

noun
  • The act of making a promise. 

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