doubt vs single-mindedness

doubt

noun

  • Disbelief or uncertainty (about something); (countable) a particular instance of such disbelief or uncertainty. 

verb

  • To be undecided about; to lack confidence in; to disbelieve, to question. 

single-mindedness

noun

  • The property of being single-minded. 

How often have the words doubt and single-mindedness occurred in a corpus of books? (source: Google Ngram Viewer )