Carl Sagan famously said that extraordinary claims demand extraordinary evidence. In this he was popularizing a Humean rule of evidence.
I’ve criticized this maxim on various occasions. Now I want to make a different point.
Unbelievers invoke this maxim because they think it undercuts the Christian faith. For example, unbelievers apply this maxim to miracles. They classify miracles as extraordinary events, then treat miracles as inherently improbable and therefore implausible for that very reason.
But let’s grant, for the sake of argument, that this is a sound maxim. The problem with this maxim is that it cuts both ways.
On the one hand, Christians don’t regard the existence of God as extraordinary. Rather, they regard the existence of God as necessary. There’s nothing extraordinary about the existence of a necessary being. To the contrary, it would be extraordinary if a necessary being did not exist. Indeed, it would be impossible.
Conversely, Christians regard nature as extraordinary. And that’s because nature is contingent. Its existence is unnecessary. Therefore, the existence of nature demands a special explanation.
Given the existence of nature, then nature is ordinary, but the given is extraordinary. As Leibniz famously said, why does something exist rather than nothing?
Beyond the general “specialness” of nature, you also have fine-tuning arguments which contend for the extraordinary character of the big bang, or life on earth, &c.
At the moment, my purpose is not to expound or defend any of these arguments. Rather, I’m making the point that Sagan’s maxim is a double-edged sword. It doesn’t carry any presumption in favor of naturalism. It doesn’t create any presumption against supernaturalism.
Both sides of the debate can begin with this maxim and draw opposing conclusions. Both sides of the debate can try to use this maxim against the other side. So this maxim doesn’t assign a distinctive or disproportionate burden of proof on the Christian. As far as the maxim is concerned, the onus falls equally on believer and unbeliever alike.