ego vs egotism

ego

noun
  • The self, especially with a sense of self-importance. 

  • The most central part of the mind, which mediates with one's surroundings. 

egotism

noun
  • Egoism (belief that behavior should be directed towards one's self-interest). 

  • A belief that one is superior to or more important than others. 

  • The result or product of being egoistic. 

  • A tendency to talk excessively about oneself. 

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