HUMAN BEINGS MIGHT be hardwired to pursue their own self-interest and do what they perceive is best for themselves, but both history and our own experience tell us human beings are equally adept at doing things that undermine their goals and hopes. In other words, humans seem very adroit at blowing it. What accounts for this apparent contradiction? In a word, sin. Sin is actually a religious word that means an offense against God. Here we expand its meaning, as is often done in common parlance, to signify any action that is against what we know we should or should not do.
Doing wrong does not promote human flourishing. This chapter explains why that is true. Nonetheless, it is true that people can think doing wrong will benefit them. It may indeed be the case that it benefits them in the short run, but it does not help them become more deeply human. People know this at some level since practically everyone agrees that doing something morally wrong diminishes them as a person. Because we are rational beings and because we understand this, we have to deceive ourselves in some fashion in order to do something that diminishes us. The deception allows us to convince ourselves that certain actions that will actually undermine our well-being are somehow going to help us.