If I had a nickel for every time I heard a non-believer claim that “extraordinary events require extraordinary evidence” I would be independently wealthy. The irony of this is that usually it’s the people who claim to be the most intellectually honest. In fact, these are the group who are quick to cast dispersions on Christians (or other theists) for committing the very crime for which they themselves are guilty.
The man credited for this idea of extraordinary events requiring extraordinary evidence is 18th century philosopher, David Hume. Hume was a materialist. His worldview was such that miracles were completely impossible on the basis that they would have to have a cause which was not materialistic. Since he did not believe in the existence of anything other than the material world, any evidence of anything which could even potentially be miraculous was dismissed out of hand.
The fact of the matter is, this criteria is demonstrably false. Just look at any lottery and you can see that this concept is not true at all. After all, it is quite extraordinary for any one person to select a series of six numbers and have it match a randomly generated series of six numbers without prior knowledge of what numbers will be generated. Yet, people win lotteries all the time and no extraordinary evidence is required to explain this.
Rather than jumping to the conclusion that extraordinary events require extraordinary evidence, it would be more accurate to say that extraordinary events require sufficient evidence, or perhaps appropriate evidence. In the lottery example, a winner coming in with their purchased lottery ticket that matches the winning numbers is not especially extraordinary evidence. After all, many people have similar tickets, just with different numbers on them. The ticket itself is hardly extraordinary. But it is sufficient to claim the prize.
Given Hume’s requirement, if it were true, then no explanation for such things would ever be adequate which would render virtually any highly improbable event as being, in effect, an impossibility and therefore the event would have to be denied. Obviously, Hume’s requirements are more stringent than necessary. Many events would have to be denied if we actually were to follow these requirements of proof for everything.
The other issue that I have with Hume’s philosophy here is the fact that the terminology is so subjective. What is extraordinary to one person could potentially be an every day occurrence for someone else. The same is true for the required evidence. Evidence that one person would consider extraordinary could be viewed as quite mundane to another. Subjective terms such as these are hardly worthy of building a world view upon as this is very shaky ground, indeed.
So, when investigating a claim, do not assume that if an event is quite improbable that it will require some enormously complex and overly exhaustive evidence. There may be a quite normal, even uninteresting explanation that is adequate to explain a certain event.
Grace, love and peace.