affirm vs contend

affirm

verb
  • To assert positively; to tell with confidence; to aver; to maintain as true. 

  • To make firm; to confirm, or ratify; especially (law) to assert or confirm, as a judgment, decree, or order, brought before an appellate court for review. 

  • To agree, verify or concur; to answer positively. 

  • To state under a solemn promise to tell the truth which is considered legally equivalent to an oath, especially of those who have religious or other moral objections to swearing oaths; also solemnly affirm. 

  • To support or encourage. 

contend

verb
  • To believe (something is reasonable) and argue (for it); to advocate. 

  • To be in opposition; to contest; to dispute; to vie; to quarrel; to fight. 

  • To be in debate; to engage in discussion; to dispute; to argue. 

  • To struggle or exert oneself to obtain or retain possession of, or to defend. 

  • contend with: To try to cope with a difficulty or problem. 

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