egoism vs soul-searching

egoism

noun
  • The tendency to think selfishly with exclusive self-interest in mind. 

  • Egotism (tendency to talk excessively about oneself). 

  • The belief that moral behavior should be directed toward one's self-interest only. 

soul-searching

noun
  • Probing introspection; a critical consideration of one's conscience; also, an instance of such consideration. 

adj
  • Involving probing introspection, or a critical consideration of one's conscience, especially motives and values. 

How often have the words egoism and soul-searching occurred in a corpus of books? (source: Google Ngram Viewer )