The tone scale is a way to rate an emotion as bad, better, or good. The scale goes from -40 ("Total Failure") to +40 ("Serenity of Being"). Positions on the tone scale started from the idea that one way of feeling is better than a worse way of feeling. But Hubbard described many other things that go along with emotion, such as health, mating behavior, survival potential, and ability to deal with truth. The tone scale is frequently used by Scientologists to understand people. According to Scientology, the lower the individual is on the tone scale, the more complex his problems are.