soothsaying vs superstition

soothsaying

noun
  • A method of foretelling the future. 

superstition

noun
  • A belief or beliefs, not based on human reason or scientific knowledge, that events may be influenced by one's behaviour in some magical or mystical way. 

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