How do some members of society bennefit through social stratification

Why does c. wright mills identify critical thinking as one of the most important criteria for the development of intellectual craftsmanship? why is constantly being aware of the biased nature of your reactions and interactions (what c. wright mills calls self-reflexive) key to the development of that critical thinking? finally, why is keeping a file important, how can it lean to intellectual curiosity which can foster critical thinking and to develop a keen analytical mind?

Some european explorers sailed west looking for the passage to india

What is a common factor all nonprofit businesses share? they pay no income tax.they have no capital.they are national in scope.they perform charitable acts.