laxity vs thoughtlessness

laxity

noun
  • Moral looseness; lack of rigorousness or strictness. 

  • The state of being lax; looseness, lack of tension. 

thoughtlessness

noun
  • heedless disregard for the consequences of one's actions 

  • disregard for other's feelings 

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