Probably worth giving the counter-point:
Scholars use sources like Tacitus and Suetonius to try to build a picture of what happened before those historians were born all the time. Often they have no choice: we only have available to us a small amount of literature from that period that is extant.
Nearly ALL literature -- pagan and Christian-- has come to us as copies of copies of copies. Most of the writings of Justin Martyr that are often used in mythicist debates today come from one source, in the year 1364:
http://www.ccel.org/ccel/richardson/fathers.x.ii.ii.html
Justin would be known to us only by a few spasmodic quotations had not a Byzantine scribe copied an invaluable, if defective, MS., in the year 1364.
But scholars of history accept this, because that is the reality of the situation. They understand the limitations. And that drives them to try to determine what corruptions and interpolations may have appeared within those texts over that long period. **
There is a hypocrisy among some mythicists that can be seen in this thread. Though they will eliminate texts as 'credible evidence' because the historian wasn't born at the time of the event they were recording, they are quite happy to use such texts to support mythicist readings, without pointing out that they are copies of copies.
If there is one thing that I think this thread demonstrates, it is that double-standard.
** Interestingly, mythicist scholars like Dr Richard Carrier and Dr Robert M Price also accept the limitations on the texts and use them in the same way as other scholars do. They don't make this point about 'the historian wasn't born then therefore it is hearsay' or 'we can't use copies of copies of copies'. Those anti-scholarly views are a feature of Internet forums. It is weird that Carrier and Price are not criticized for doing the same things. IanS, Mcreal: you need to teach Dr Carrier and Dr Price the truth about how to use those texts! Tell them where they are going wrong!