lunacy vs understanding

lunacy

noun
  • a cyclical mental disease, apparently linked to the lunar phases 

  • insanity implying legal irresponsibility. 

  • Something deeply misguided. 

understanding

noun
  • Opinion, judgement or outlook. 

  • An informal contract; mutual agreement. 

  • A reconciliation of differences. 

  • The act of one that understands or comprehends; comprehension; knowledge; discernment. 

  • Sympathy. 

  • Reason or intelligence, ability to grasp the full meaning of knowledge, ability to infer. 

adj
  • Showing compassion, tolerance, and forbearance. 

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