Dark is a relative term...

As one who loves history, I have long been frustrated by the shallow characterization of the period after the fall of the Roman Empire as the Dark Ages.  Dark is a relative term.  A perfectly well lit room seems dark when you enter from the bright sun.  So it is with the period leading up to the bright light of the Renaissance and after the bright light of the Roman Empire.

Here is a little video that might perk up some discussion on the subject.