Illustrating the burden of proof - pay me!

[Mister Agenda]

Neo, what is the reason for god? Or do you accept god as a brute fact?

Not at this time. The question of God's existence howver seems to me inextricably connected to things I do consider brute facts such as the Principle of Non-Contradiction.

Isn't it part of the Principle of Sufficent Reason that there are no brute facts?

---

The aphorism 'extraordinary claims require extraordinary evidence' has been brought up as an example of arguing from incredulity. It can (and has) been misused that way, 'extraordinary' is very ambiguous in common language. But it isn't meant to be a prop for personal incredulity, the term 'extraordinary claim' should be be understood as a claim contrary to what known prior evidence supports, and 'extraordinary evidence' is evidence sufficient to indicate the claim is correct in the face of evidence to the contrary.

If I claim to be able to levitate my body by force of will, I'm claiming something extraordinary, there is no known mechanism for such a feat and being able to rise against gravity without propulsion defies what we know of the laws of physics. I shouldn't expect to be believed without demonstrating my ability repeatedly under controlled conditions. If you believe me without that level of evidentiary support, probability is not on your side. It would be puerile of me to insist that your main reason to disbelive my claim is your subjective sense of personal incredulity. If I am successful in demonstrating my amazing power repeatedly under controlled conditions with a wide variety of observers, I can expect to be a source of worldwide scientific amazement and probably the basis for establishing a new branch of science to study what I can do.

If I claim to be able to walk around the block using my legs and feet, it's well known that most people can do that, so it's an 'ordinary claim' and it's reasonable to take my word for it unless you know a particular reason to disbelieve it (like you had me under surveillance or you know I'm a bedridden parapalegic...I'm not, btw).

---

How do you meet in the middle when deciding who has the burden of proof for the claim that both share the burden of proof?

It's not the middle, but I think it's helpful to consider who is making the positive claim. If one side would be put in the position of trying to prove a universal negative, they don't really have the burden of proof, even if they brought it up first. It's undertood that their negative claim is a reaction to some other positive claim. If someone asserts that there are no such things as magical leprechauns, it's understood that the statement is a response to the idea that there ARE such things as magical leprechauns, even if no one in that particular conversation asserted that there are. The person you're talking to may not have claimed there are, but if they're going to disagree with the proposition, it's on them to demonstrate sufficient reason to believe leprechauns are real. As a matter of courtesy, you probably shouldn't assert there are no leprechauns apropos of nothing without being prepared to explain your reasoning if someone disagrees, but in the absence of contrary evidence, that's the default position no matter who brings it up first.

If it's not a universal negative, the person who asserts it (there's no visible elephant in my garage) has the burden of proof.