| | Ronald A. | Howard | An extraordinarily gifted professor at Stanford. |
| | Sam | Harris | Narrator and author. |
| | Sissela | Bok | Philosopher. |
| | Sita | | Sam's friend who lied about where she got her gift for another friend. |
| | Jessica | | Lucy's fiend. |
| | Lucy | | Jessica's friend. |
| | Daniel | | Sam's friend. |
| | Stephanie | | Gina's friend. |
| | Gina | | Stephanie's friend. |
| | Derek | | Gina's husband. |
| | (Immanuel) | Kant | Philosopher. Believed lying was unethical in all cases. |
| | Lance | Armstrong | Professional road racing cyclist. |
| | Tiger | Woods | Professional golfer. |
| | John | Edwards | Former US senator. |
| | Eliot | Spitzer | Former Governor of New York. |
| | Anthony | Wiener | Former US representative. |
| | Andrew | Wakefield | Physician. |
| | Anne | Frank | German diarist. |
| | Clint | Korver | A doctoral student. |
| | Lao | Tzu | Chinese philosopher. |
| | Janet | Malcolm | Writer. |
| | Joe | McGinnis | The best-selling author of Fatal Vision. |
| | Jeffrey | Macdonald | A green beret physician convicted of murdering his pregnant wife and two daughters. |
| | Daniel | Ariely | Behavioral economist. |