Ronald Syme (1903-1989), Tacitus
, Vol. I (1958; rpt. Oxford: Clarendon Press, 1997), p. 291:
Rigid dogma has not infrequently been invoked to arraign and condemn the historians of classical antiquity. For all that they appeal to a plurality of authorities and adduce names or facts, they shall not be taken at their word. It is only convention, and it may be deception: the historian generally selects a single source and adheres to it closely; he abbreviates rather than supplements; and, if he alters, it is style not substance that is modified.5
In this dogma there are manifold attractions: the scope of historical inquiry can be narrowed on the plea of precision, the idiosyncrasy of a writer dismissed as irrelevant or barely existent.6
5 H. Nissen here set the fashion, but should not he blamed for all the extravagances of the epigoni.
6 cf. p. 190, with App. 29 (on the Historiae).