I do not believe that there is a country in the world where, in proportion to the population, there are so few ignorant
and at the same time so few learned individuals. Primary
instruction is within the reach of everybody; superior
instruction is scarcely to be obtained by any. This is not
surprising; it is, in fact, the necessary consequence of what
I have advanced above.
-Alexis de Tocqueville, Democracy in America
What is the central theme of this excerpt?