If you tell the truth, you possess the quality of honesty. If someone offers a harsh criticism of your latest attempt at songwriting, you might say, "Thank you for your honesty." Even if you don't mean it.
The original meaning of honesty had more to do with honor than truthfulness, although the two are naturally linked. The trait of honesty has been prized for centuries, and Shakespeare once wrote, "Honesty is the best policy. If I lose mine honor, I lose myself." The honesty flower, sometimes called the money plant, is so named because its coin-shaped seedpods are translucent, the idea of transparency symbolizing integrity.