self-control vs volition

self-control

noun
  • The ability to control one's desires and impulses; willpower. 

verb
  • To control oneself or itself. 

volition

noun
  • The mental power or ability of choosing; the will. 

  • A conscious choice or decision. 

  • A concept that distinguishes whether or not the subject or agent intended something. 

How often have the words self-control and volition occurred in a corpus of books? (source: Google Ngram Viewer )