according to (one's) own lights
Based on one's beliefs or inclinations. You may not agree with Kara's free-spirited lifestyle, but she has always lived according to her own lights.
according to one's own lights
according to the way one believes; according to the way one's conscience or inclinations lead one. John may have been wrong, but he did what he did according to his own lights.
according to your lights
in accordance with your own personal standards of morality or propriety.