ebullience vs pessimism

ebullience

noun
  • A boiling or bubbling up; an ebullition. 

  • The quality of enthusiastic or lively expression of feelings and thoughts. 

pessimism

noun
  • A general belief that bad things will happen. 

  • The condition of being pessimal. 

  • The doctrine that this world is the worst of all possible worlds. 

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