Theist (T): My belief in God is not based on blind faith. It is based on evidence. How can you deny the countless reports of miracles going back thousands of years?
Atheist (A): They are all anecdotes. Anecdotal evidence alone is never sufficient. It must be supported by controlled experiments and observations.
T: But how can you explain all those reports?
A: Without details on the observations, I can only offer possible explanations.
T: OK, what are those?
A: Delusions, hallucinations, even outright lying and fraud.
T: You cannot prove any of these. And how unjust of you to accuse people of fraud without proof! Whatever happened to the principle that you are innocent until proven guilty?
A: That principle may be fine in a law court, but these are not legal questions but scientific ones. In science you are guilty until you prove yourself innocent. Besides, I made no accusations. I only said I was going to offer possible explanations. Fraud is one possible explanation among the others. That is the problem with anecdotal tales. Not enough data are available to determine the true explanation.
T: Then your possible explanations are no better than my equally possible explanation–that God enacted these miracles.
A: No, I disagree that your explanation is equally possible. My explanations are based on well-established facts: People have been known to be deluded, have hallucinations, and lie. These explanations are unexceptional and so must be ruled out before you can consider extraordinary explanations that are not based on well-established facts.
T: Well, many miracles are well-established facts. Take weeping icons and stigmata, for example. They have been witnessed by many people, including skeptics.
A: Yes, these phenomena have been observed by skeptics. But they are not miraculous. Natural explanations have been given and the effects duplicated by investigators. They could be honest psychological effects. Or, they could be faked. For example, go into a church early in the morning and rub some Mazola oil on a stained glass window, say on the face of the Virgin Mary. When the sun later shines through the window, the oil will warm and trickle down like tears. Other substances placed on statues in churches produce a similar effect, looking like tears or blood. As the church fills with worshippers, it warms and the substance melts. As for stigmatists, many have been discovered to wound themselves. For detailed explanations of these types of miracles, see Looking for a Miracle by Joe Nickell.