"There are known knowns. These are things we know that we know. There are

known unknowns. That is to say, there are things that we know we don't know.

But there are also unknown unknowns. There are things we don't know we don't

know," Donald Rumsfeld

In a multicultural society, the orthodontist is often faced with the challenge of
interpreting an individual’s aesthetic preferences, which depending on the individual
might differ from Eurocentric standards. Psychological researchers have recognized that ethnicity is dynamic, and better defined as a perception of self, influenced by social interaction and cultural involvement.

In these days, and they are hardly more than half a lifetime
behind us, no one thought of any sort of world administration.
That patchwork of great Powers and small Powers seemed the
most reasonable and practicable method of running the
business of mankind. Communications were far too difficult for
any sort of centralised world controls. Around the World in
Eighty Days, when it was published seventy years ago, seemed
an extravagant fantasy. It was a world without telephone or
radio, with nothing swifter than a railway train or more
destructive than the earlier types of H.E. shell. They were
marvels. It was far more convenient to administer that world of
the Balance of Power in separate national areas and, since there
were such limited facilities for peoples to get at one another
and do each other mischiefs, there seemed no harm in ardent
patriotism and the complete independence of separate
sovereign states.

"There are known knowns. These are things we know that we know. There are

known unknowns. That is to say, there are things that we know we don't know.

But there are also unknown unknowns. There are things we don't know we don't

know," Donald Rumsfeld

In a multicultural society, the orthodontist is often faced with the challenge of
interpreting an individual’s aesthetic preferences, which depending on the individual
might differ from Eurocentric standards. Psychological researchers have recognized that ethnicity is dynamic, and better defined as a perception of self, influenced by social interaction and cultural involvement.

In these days, and they are hardly more than half a lifetime
behind us, no one thought of any sort of world administration.
That patchwork of great Powers and small Powers seemed the
most reasonable and practicable method of running the
business of mankind. Communications were far too difficult for
any sort of centralised world controls. Around the World in
Eighty Days, when it was published seventy years ago, seemed
an extravagant fantasy. It was a world without telephone or
radio, with nothing swifter than a railway train or more
destructive than the earlier types of H.E. shell. They were
marvels. It was far more convenient to administer that world of
the Balance of Power in separate national areas and, since there
were such limited facilities for peoples to get at one another
and do each other mischiefs, there seemed no harm in ardent
patriotism and the complete independence of separate
sovereign states.