Why do people work?

There is an article on the Harvard Business Review Blog that contrasts two views of economic activity:

• "In economics, consumption is the sole end of production,"
• "[T]here are many people who live in order to work, who consume in order to produce."

I was a Peace Corps Volunteer. I am not sure that either view covers those like most PCVs who produce not so much as for consumption nor for the work per se, but rather to do good. There have been more than 210,000 PCVs, and they are only a small portion of the people who work for civil society organizations.