Theology 1.0: What is poisoning the well?

An ad-hoc fallacy
Imagine two people having a debate. The first man begins by denouncing his opponent of being liar, an adulterer and untrustworthy person.

His statement (while it made be true) is an ad-hoc fallacy. It is an attempt to disprove an argument by discrediting the person. In debates, this tactic is called "poisoning the well" (Sire, 2006).

But how does this apply to apologetics?
In our attempts to reason with our non-believing friends, we may unwittingly use such tactics. Let's see some example statements:

"This person doesn't know anything about theology."

"He comes from a church that promotes materialism."

"She does not come from a reputable school."

Sometimes, the tables get turned. For instance, my Christian friends and I have been accused of being "fundamentalists", "imposing morality" and "misguided idealists".

Conclusion
Every argument should be treated on its own merit, and should be independent of the reputation of the person making the argument.



References
Sire, J.W. (2006) Why good arguments often fail