ability vs weakness

ability

noun
  • The quality or state of being able; capacity to do or of doing something; having the necessary power. 

  • A unique power of the mind; a faculty. 

  • A skill or competence in doing; mental power; talent; aptitude. 

  • Physical power. 

  • The legal wherewithal to act. 

weakness

noun
  • The condition of being weak. 

  • An inadequate quality; fault 

  • A special fondness or desire. 

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