Recently, I came across a reference to Garrett Hardin and his Invisible Foot. Also known as the Tragedy of the Commons, in simplest terms, it is the battle between the individual interest and common good on a resource that is finite. Wikipedia says "It is a structural relationship between free access to, and unrestricted demand for, a finite resource". Its called the Tragedy of Commons because every individual is acting rationally and still ends up destroying the resources and Commons because the resources under scanner are free for everyone to use.
The Invisible Foot is often used alongside Invisible Hand by Adam Smith to explain the principles of economics. " The Invisible Hand" says that a person acting in self interest acts as if he is guided by an individual hand trying to work for the good of the mankind. So basically every time there was a breakthrough (evolution or business), the individual did it for his own benefit and ended up benefiting the entire mankind. For example, in Natural Selection - Individual started differentiating itself from others to gain an edge over members of the same species and it ended up making the entire species stronger ( Survival of the fittest). In business, with every new breakthrough product, individuals trying to corner more market share and making money actually helped mankind take a leap (example use of CDs instead of Tapes).
According to Adam Smith every subsequent improvement by an individual brings that individual benefits and helps the world to move forward. Here resources are infinite and everyone can capture large market share happily.
And according to Garrett Hardin, every subsequent improvement by an individual brings benefits to that individual but degrades the quality of resource. This resource is limited and with every subsequent chunk being taken by an individual reduces the availability and quality of the resources.
Both of these are very interesting theories. Both talk about actions of individuals. Hope I could understand them better.