Is conscience a more powerful motivator than money,fame,or power?please help!!?

i have to wright an essay about that topic so if you have any ideas please help...A mistakenly cynical view of human behavior holds that people are primarily driven by selfish motives: the desire for wealth, for power, or for fame.Yet history gives us many examples of individuals who sacrificed their own welfare for a cause. Conscience(that powerful inner voice that tells us what is right and what is wrong)can be a more compelling force than money,power, or fame?