common sense vs hot air

common sense

noun
  • Ordinary sensible understanding; one's basic intelligence which allows for plain understanding and without which good decisions or judgments cannot be made. 

hot air

noun
  • Air that has been heated, especially so as to function as the lifting agent of a hot-air balloon. 

  • Empty, confused, or exaggerated talk lacking meaning or substance; bluster. 

How often have the words common sense and hot air occurred in a corpus of books? (source: Google Ngram Viewer )