assume vs tell truth

assume

verb
  • To receive, adopt (a person) 

  • To adopt a feigned quality or manner; to claim without right; to arrogate 

  • To authenticate by means of belief; to surmise; to suppose to be true, especially without proof 

  • To take on a position, duty or form 

  • To adopt (an idea or cause) 

tell truth

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