lethargy vs stoicism

lethargy

noun
  • A state of extreme torpor or apathy, especially with lack of emotion, energy or enthusiasm; (loosely) sluggishness, laziness. 

  • A condition characterized by extreme fatigue or drowsiness, deep unresponsiveness, or prolonged sleep patterns. 

stoicism

noun
  • A real or pretended indifference to pleasure or pain; insensibility; impassiveness. 

  • A school of philosophy popularized during the Roman Empire that emphasized reason as a means of understanding the natural state of things, or logos, and as a means of freeing oneself from emotional distress. 

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