blameless vs principled

blameless

adj
  • Not meriting blame or censure; undeserving of reproof. 

  • Free from blame; without fault; innocent 

principled

adj
  • strongly adhering to, or heedful of, guiding beliefs or moral rules 

  • Based on, having, or manifesting principles 

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