In Defence of Periodization
Periodization is the division of history into periods. Throughout a given period, certain historical features remain more or less constant. Throughout the Greek Dark Age (ca. 1200-800 BC), for instance, Greece was devoid of urban life.
Periodization is inherently approximate. A period system takes a vast, complex stream of events and simplifies it into tidy units according to dominant trends, allowing scholars to understand the "big picture".
Periodization is sometimes dismissed as oversimplification. A well-designed period system, however, can only be perceived as oversimplified if misinterpreted. For instance, urban life did not disappear from Greece overnight ca. 1200 BC, only to instantly reappear ca. 800 BC; these transitions were gradual. Such misinterpretation is impossible, however, for any but the most novice of history students.
Properly constructed, periods are not oversimplifications, but simplifications of an appropriate degree. (The "appropriate degree" will naturally vary according to the purposes of the individual scholar.) Indeed, the only way to understand any complex matter is via strategic simplification.