Mancur Olsen
This passage point out the selfish ways of human. The author believes that even when an individual appears to be acting selflessly the reality is they are always going to work for something that benefits them n a personal level. In other words, an individual will not do anything that does not work to further their personal interest. When individuals unite to form a group of some sort it is in attempts to further their personal gain with the help of others and not in attempts to help the others of the group further their collective interest.
I believe there is truth in this quote. An individual will not join the fight of others unless they themselves are directly affected by the problem. Often we choose to stand by idling while others around us experience hardships. I do think that some good can come from this. Once we realize that we are affected and choose to join the action, one large collective voice is more powerful than a large number of single voices speaking for themselves. Forming groups provides the individuals with more force than they could develop independently.