need vs substance

need

noun
  • A requirement for something; something needed. 

  • Lack of means of subsistence; poverty; indigence; destitution. 

verb
  • To be obliged or required (to do something). 

  • To be required; to be necessary. 

  • To want strongly; to feel that one must have something. 

  • To have an absolute requirement for. 

substance

noun
  • The essential part of anything; the most vital part. 

  • Physical matter; material. 

  • Material possessions; estate; property; resources. 

  • Hypostasis. 

  • Drugs (illegal narcotics) 

  • Substantiality; solidity; firmness. 

  • A form of matter that has constant chemical composition and characteristic properties. 

verb
  • To give substance to; to make real or substantial. 

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