Can you name a belief for which there is no evidence whatsoever?
Yes, my belief that there is an invisible, flying, horseshoe-crab-like creature that follows me around sometimes. You know once I figure out how to capture the darn thing I'll be famous. I'll just spray paint it and show it to everyone, they'll all be sorry they laughed at me then, won't they? Also, I think it'll make a good pet.
Now, prove this isn't true.
There is evidence of the existence of God (a lot of it actually). Whether you would find the evidence compelling is another matter, but there is plenty of it.
Great, present some of this fabled evidence already. Hopefully, it will as irrefutable as the fact that life existing on Earth shows that life is possible.
Accepting ONLY the proposition that intelligent life exists here does not necessarily lead to the conclusion of even the possibility of intelligent life existing elsewhere.
Yes it does. There is nothing that separates Earth and this solar system from the rest of the universe. The stuff that makes up this solar system is abundant throughout the universe. The physical laws that exist in this solar system appear to exist throughout the universe. If it is possible here, it is possible throughout the universe, because there is nothing fundamentally different between the two. We have irrefutable evidence that it is possible here, so it logically follows that it is possible throughout the universe. The only way around this is to claim that it is not possible here and life came about through some supernatural event or prove there is a fundamental difference between this solar system and the rest of the universe.
The only argument that leads necessarily to the conclusion of the possibility of intelligent life existing elsewhere (despite the lack of any objective evidence of its existence) is the fact that it's not impossible.
What does this mean? So by this argument, it is just as rational to believe my horseshoe-crab-like creature exists as it is to believe that God exists? Glad we agree, was starting to actually believe some of the people that said I was crazy.
It is without a doubt true that both are possible. Neither can be "more possible" than the other.
No, but one can be more rational than the other based on the available evidence.
The fact that the existence of God and the existence of intelligent life outside of our solar system are both unfalsifiable does, in fact, make them both possible.
They are not both unfalsifiable in the same way. The existence of life elsewhere in the universe is unfalsifiable claim only by practical limitations. Theoretically, we could search every star and planet in the universe, and after finding nothing, know for a fact life elsewhere does not exit. Doing the same will not prove God does not exist. It seems by the very definition of God, there is no possible way of proving God does not exist.
In order to determine that one belief is necessarily more or less rational than another, you would have to have some objective means of determining which is more probable. In this case, I don't think you can objectively determine the probability of either except to say that they are both greater than 0% and less than 100%.
The probability is not the only way to determine which is a more rational option. You can also use the quality of evidence used to support that the possibility actually exists to determine which is more rational. In the case of life elsewhere, we have evidence that life is possible and logic to say that if it is possible here that it must be possible elsewhere (see above). In the case of God existing, we only have a definition that makes it impossible to falsify the claim, like that irritating horseshoe-crab-like creature. I think I should name him, his description is kind of long to write.
Again, we have yet to discuss any case where there is no evidence at all.
See above.
I think you may be misunderstanding my use of the word. I wasn't using it to indicate whether or not something might turn out to be true. It is a fact that it cannot be proven that either God or intelligent life elsewhere are impossible. Therefore, it is true that they are possible.
Both possible, yes. Equally rational, no.
What empirical evidence do you have that intelligent life exists outside of our solar system?
-Bri
Who claimed that? I said we have empirical evidence to show life is possible, and logical reasons to believe that what is possible in this solar system is possible throughout the universe.