forethought vs thoughtlessness

forethought

adj
  • Thought of, or planned, beforehand. 

noun
  • Anticipation. 

  • Provident care; prudence. 

  • Thinking beforehand or in advance, planning; prior or previous consideration; premeditation. 

thoughtlessness

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

  • disregard for other's feelings 

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