Ok, I would like to ask something to make sure that I understand correctly.
Santa Claus is a fairy story for kids. There's not really a jolly fat man living with elves at the North Pole and making toys to deliver to children from his flying sleigh on Christmas Eve.
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I'm not open to new evidence for any of that because it's all definitively wrong. There will never be any valid evidence in favor of those positions because there cannot be. If those things were right, the world wouldn't be the way we know it is.
Let's consider the following scenario: You wake up tomorrow and find a jolly fat man sitting next to your bed. He introduces himself as Santa Claus and snaps his fingers. The next moment, you will find yourself in the middle of freezing polar landscape, where you observe green little creatures manufacturing toys and what looks like a sleigh pulled by flying reindeer. The man then goes on to explain how it is possible for him to exist without having been observed, answering your questions, even going all the way to explain new quantum physical theories that are consistent with both his existence and the appearance of the world as you had known it, should you be interested and able to follow the math. He will introduce you to specific predictions of "Santa Claus existence hypothesis" that you can at any later time test with simple experiments (for example, a chant that you can recite to make him appear at any time and place). Then you will find yourself back at your home again, retaining the ability to perform the mentioned experiments, which will give positive results any time you or anyone else tries them.
Now, can you please clarify what your position is?
1. Given this scenario, you would conclude that all this apparent evidence must be invalid (fake, illusory, etc.), because it was already determined that there cannot be any valid evidence for the existence of Santa Claus. Even given arbitrary amount of time and experiments that would seem to confirm the hypothesis, you would refuse to acknowledge its plausibility. You will attempt to find an explanation for all these strange observations that would be consistent with Santa Claus' non-existence, such as drugs, hallucinations, insanity, being trapped in a virtual reality, etc. If these hypotheses are ruled out or unsupported by further experimentation, you will admit that you cannot explain your observations, but you will still maintain that these observations do not constitute valid evidence for the existence of Santa Claus, because such valid evidence cannot exist.
2. The question of what you would do given this scenario is fundamentally meaningless, because this scenario cannot occur. This is because the observations described earlier would, by definition, constitute valid evidence for the existence of Santa Claus, and such evidence cannot exist, therefore such observations cannot possibly be made. - In other words, the sequence of bodily perceptions that would make up these observations is physically impossible in this universe, and cannot be achieved by any means, including, but not limited to, drugs, hallucinations, insanity, or sensory/neural manipulation.
3. Something else - please elaborate.
Please do not take this as an argument. I'm not trying to make a point; instead, I genuinely want to make sure that I fully understand what your position is.