One of the greatest paradoxes that Socrates helped his students explore was whether weakness of will—doing wrong when you genuinely knew what was right—ever truly existed. He seemed to think otherwise: people only did wrong when at the moment the perceived benefits seemed to outweigh the costs. Thus the development of personal ethics is a matter of mastering what he called “the art of measurement,” correcting the distortions that skew one’s analyses of benefit and cost.