When he comes to the empire, moreover, he is very careful to specify to a day the exact duration of each emperor's reign, and in certain other matters aims at equal exactness. Yet in spite of all his pains in this regard it would often be extremely difficult or impossible to extract a consistent chronology from his data. For it frequently happens that in his desire to trace the causes or results of a given series of events he is led to exceed the limits of a single year by a considerable margin; occasionally also this same motive is responsible for an inversion of the actual order of events.
Unfortunately the value of his history is greatly diminished for us as the result of his blind devotion to two theories governing historical writing in his day. On the one hand a sense of the dignity and true value of history demanded that mere details and personal anecdotes should give place to the larger aspects and significance of events. On the other hand the historian was never to forget that he was at the same time a rhetorician; if the bare facts were lacking in effectiveness, they could be adorned, modified, or variously combined in the interest of a more dramatic presentation. These two principles, as applied by Dio, have resulted all too frequently in a somewhat vague, impressionistic picture of events, in which precisely those data which the modern historian eagerly looks for are either largely wanting
- LXXII, 18, 3.