observant vs perverse

observant

adj
  • Diligently attentive in observing a law, custom, duty or principle; regardful; mindful. 

  • Alert and paying close attention; watchful. 

perverse

adj
  • Morally wrong or evil; wicked; perverted. 

  • Obstinately in the wrong; stubborn; intractable. 

  • Turned aside while against something, splitting off from a thing. 

  • Ignoring the evidence or the judge's opinions. 

  • Wayward; vexing; contrary. 

verb
  • To pervert. 

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