Selfishness is a concept that surprisingly sees a lot of debate. Of course, it is a loaded term with which only a few would choose to be willingly associated. Those who choose to call themselves selfish and laud its virtues—such as Ayn Rand—undoubtedly reject its negative connotations. On the other side, the word is used by altruists and hypocrites alike as mud to childishly sling in the faces of people who are not so fearless around the word as others.
In this way, it is one of the chief "weapons" used in philosophical debate among today's media. I don't agree with everything Ayn Rand says, but I appreciate her willingness to own an empty, derogatory term. To be sure, selfishness—and all things linked to its roots—is an inseparable part of the human experience. In itself, it is neither good nor bad, but a fact to be taken under consideration. Interestingly, it does not follow the set rules that either side wants to believe it does.
The so-called "Right Wing" believes in the motivational power found in selfishness. They understand that it is an irrevocable fact of humankind, which is better to work with than against. However, they often ignore its weaknesses in favor of its strengths. On the other hand, the "Left" sees selfishness as public enemy number one. They wish it could be bred out, regulated into obsolescence, or forced into submission. They believe in altruism and that a perfect society is one where people serve the whole.
Both these perspectives are accurate, but each only half-true. It is true that many people in many cases actively pursue their own selfish interests, and that rewarding productive behavior encourages productive behavior. Many, but not all. It is also true to say that a society of individuals who each sacrifices his self-interest for the good of the whole would prosper long term. The problem is that, in reality, no one is a purist. One might be a purist for a period of time (or even a lifetime) but this is a rare happenstance and will never be the rule.
As a drive, selfishness always falls short of what would cause society to prosper. Despite what many believe, most people reach an equilibrium at work. They get to the point in life where money satisfies enough desires that taking on more effort is not worth it. People don't run all the way to millionaire just for the money—they do it because they have a vision, something pulling on their hearts. They see a change to help others (altruism) and they chase it, and indeed, that is the only way one gets to be nouveau riche.
But as for the heart, charity has to be something special. When a government program, special interest group, or other similar organization distributes funds to people, it isn't charity—it's entitlement. Most people don't feel compelled to give back to these organizations, they just want more support. It's one of the stranger sides of selfishness. When people are given money for being something they had no control over, they generally don't appreciate it as a gift. To ignore this fact, and to build an organization upon status distribution is to create slaves to your organization.
Seek to understand selfishness, and moreover, how it is manifested in each individual you meet. Work with it, rather than against it, but never assume it is a mechanical push-button, because it will let you down at a critical moment.