The Default Position

When asked to examine a claim (more often than not, about supernatural events/entities), rationalists sometimes speak of the "default position". What about it?

Faced with any claim, the default position is disbelief until belief is warranted (by weight of sufficient evidence).

That simply means "I do not believe X exist until sufficient evidence is brought forth to demonstrate X's existence." That is very different from "I believe X do not exist." While it is tempting to equate the two statements, they are, in fact, two very different positions.

To illustrate the different positions, I'll use the court of law as an example.

Say we have a murder case and it's time for the judge to make their vote. He/she may judge that the accused is
[1] - Guilty
[2] - Not guilty

If the judge is convinced by the prosecutor that the accused is indeed the murderer, he would judge guilty. However, when the judge judges the accused to be not guilty, he/she may be holding one of two positions.

If the judge thinks that the accused is innocent, he/she judges the accused to be not guilty. If the judge thinks that the evidence is insufficient to make the case, he/she also judges the accused to be not guilty. Belief that the accused is innocent is not the same as being unconvinced to the contrary.

The same scenarios apply for claims of existence. While existence is absolute (either it exist of it does not), our state of belief can be one of the following:
[1] - I believe X exist
[2] - I believe X does not exist (Assertion)
[3] - I don't believe X exist (Negation)

One may ask, where is the fourth option that "I don't believe X does not exist". Using the court of law analogy, this option's equivalent would be "Guilty - I am not convinced of the accused's innocence."

Why is this option eliminated? Simple. It is same reason for the phrase "innocent until proven guilty". The fourth option presents the situation where it is "guilty until proven innocent". To avoid punishing an innocent mistakenly, this must be the case.

As for claims of existence, the equivalent reason has been said before - Non-existence until existence is demonstrated (That's the practical way of saying disbelief in existence of X until its existence has been demonstrated).

The elimination of the fourth option follows the same principles. If we took the position "belief existence until disproven", we would have to believe in an infinity of possible entities until they are disproven. That is not only impractical but just plain stupid and irrational.