Selection bias notwithstanding, we exist, which means life evolved at least once. If the universe can give rise to life it would be extremely odd that it did so exactly once.
That doesn't address the point I'm making. Which is that if the universe can give rise to life, it's more likely to have multiple instances of it than for it to be exactly one. In the same way that it takes more effort to ensure you fill a swimming pool to be so full as to overrun by exactly one drop and no more, than it is to fill it imprecisely and either have no spillage at all because it's nowhere near full or lots of spillage because it's now too full.
You have to be careful to define "universe" here. It's not necessarily what we'd call the observable universe. It might, for example, be all the various branches of a universal wave function defining a vast array of possible universes, none of which could ever observe the others. It could also include sections of space time forever beyond our observational horizon (due to the apparently nonzero cosmological constant.)
ET intelligences arising in those inaccessible places would never be able to land here on Earth.
You've created an axiom that says "randomized sample sizes are the only source of knowledge".
So of course it follows that you keep saying we know nothing about aliens and must reject speculation from what we know of the laws of physics. But it's only as true as the axiom that led you to that conclusion.
It doesn't strike me as a very compelling argument. In practice, every human believes things that don't have random sample sizes that prove their existence.
No, I'm just pointing out that regardless of how rare we are, we'd see ourselves. Our observation of ourselves is consistent with any theory where the probability that we would exist is > 0. Therefore, such an observation cannot rule out any such value for p. Randomized sample size (whatever the hell you mean by that) has nothing to do with anything.
Okay, I think I understand you now. You are making a well debated philosophical argument which appears to fall under the term "anthropic objection", and philosophers have defended or attacked your position. (though it gets a bit confusing since some of the discussion has been around intelligent life in the universe in the context of religious beliefs, and other versions have nothing to do with religion.)
I found one rebuttal here saying that applying your line of reasoning to other topics besides the existence of intelligent life leads to absurd results:
"Critics of the anthropic objection argue that Sober’s reasoning delivers highly implausible results when transferred to examples where rational inferences are less controversial. Most famous is Leslie’s firing squad (Leslie 1989: 13f.), in which a prisoner expects to be executed by a firing squad but, to his own surprise, finds himself alive after all the marksmen have fired and wonders whether they intended to miss. The firing squad scenario involves an observation selection effect because the prisoner cannot contemplate his post-execution situation unless he somehow survives the execution. His observations, in other words, are “biased” towards finding himself alive (see Juhl [2007] and Kotzen [2012] for further useful examples). Sober’s analysis, applied to the firing squad scenario, suggests that it would not be rational for the prisoner to suspect that the marksmen intended to miss (unless independent evidence suggests so) because that would mean overlooking the observation selection effect that he faces. But, as Leslie, Weisberg (2005) and Kotzen (2012) argue, this recommendation seems very implausible."
No, I'm just pointing out the simple fact that we could not observe ourselves if we did not exist. We cannot take Earth as a random sample of places in the universe, for this reason. The more rare planets like Earth are, the more biased our observations of Earth become.
The firing squad example there has other prior information that we lack when it comes to understanding our own existence. The analogy is only as good as the correspondence between the cases, and assuming that correspondence is a circular argument.
I don't understand why you wrote "no" when I referenced philosophers. Are you saying every idea in your post was an original thought to yourself, and you weren't repeating someone else's ideas without attribution? If so, congratulations, you recreated some interesting ideas, but they shouldn't hard to rebut, as others have already done it. You are free to accept the rebuttal as correct or not correct, but you seem to be frustratingly confusing philosophical arguments with facts.
Let's break down what you wrote:
"Observer selection bias makes our own existence entirely irrelevant to the question of whether there are other intelligences out there."
This is not a "fact" but a philosophical claim about how to account for observer selection bias. Your proposed solution appears to be to shut down all discussion of the topic of what the existence of humanity tells us about the likelihood of alien life.
You also wrote:
"The firing squad example there has other prior information that we lack when it comes to understanding our own existence."
This is not a factual statement but rather a philosophical claim that the entire fields of biology and astronomy contain no relevant "other prior information" as to our understanding of our existence.
My "no" is your incorrect conclusion that what the philosophers were saying is relevant to what I was saying. The error is not that of the philosophers, the error is yours.
Well, at this point I think you are plagiarizing other people's ideas and then asserting the rebuttal of those ideas can't possibly apply to anything you wrote here.
