authority vs soundness

authority

noun
  • Status as a trustworthy source of information, reputation for mastery or expertise; or claim to such status or reputation. 

  • A reliable, definitive source of information on a subject. 

  • Persons, regarded collectively, who occupy official positions of power; police or law enforcement. 

  • Official permission; authorisation to act in some capacity on behalf of a ruling entity. 

  • A government-owned agency that runs a revenue-generating activity for public benefit. 

  • Power or right to make or enforce rules or give orders; or a position having such power or right. 

soundness

noun
  • The property (of an argument) of not only being valid, but also of having true premises. 

  • The result or product of being sound. 

  • The property of a logical theory that whenever a wff is a theorem then it must also be valid. Symbolically, letting T represent a theory within logic L, this can be represented as the property that whenever T⊢𝜙 is true, then T vDash 𝜙 must also be true, for any wff φ of logic L. 

  • The state or quality of being sound. 

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