A history of British butterflies cannot be separated from that of their collectors, since our knowledge of them is the result of four hundred years of collection and study. A mere fifty years ago many now uncommon species were widespread and abundant - their subsequent seemingly irreversible decline ...
A scholar of Hellenistic and Prussian history, Droysen developed a historical theory that at the time was unprecedented in range and depth, and which remains to the present day a valuable key for understanding history as both an idea and a professional practice.