"Tacitus, in certain respects an utter fool"

It's not every day that you run across one of the leading modern historians of the Roman Empire calling the man generally regarded as the finest ancient Roman historian "an utter fool", but that is what Ramsay MacMullen has to say about Publius Cornelius Tacitus in his Roman Social Relations 50 B.C. to A.D. 284.

Here, for the record, is the passage, which illustrates the "almost incredible snobbery" of Rome's minute upper crust:

Citizens of the capital felt themselves vastly superior to men of any other origin.  Tacitus lists "among so many sorrows that saddened the city" in the year 33 the marriage of a woman of the royal family to someone "whose grandfather many remembered as a gentleman outside the Senate, from Tivoli" - the horror of the mesalliance lying no more in equestrian rank than in the stain of small-town birth a bare two generations ago.  If we ask who "the city" is that felt such grief, and who "the many" are who reckoned up the inadequate years since immigration to Rome, we lay bare an almost incredible snobbery.  For Tacitus, in certain respects an utter fool, only the few thousands of his own circle really existed.

Prof. MacMullen's reference is to Annals 6.27.  The woman in question was Julia, the daughter of Drusus the Younger. The marriage that so saddened the city was to Gaius Rubellius Blandus.