optimism vs vitality

optimism

noun
  • the doctrine that this world is the best of all possible worlds 

  • a tendency to expect the best, or at least, a favourable outcome 

  • the belief that good will eventually triumph over evil 

vitality

noun
  • That which distinguishes living from nonliving things; life, animateness. 

  • Energy or vigour. 

  • The capacity to live and develop. 

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