OK, this is going to come off as more of a rant. I've recently gotten into a discussion... wait, no, let me restart that. I've recently been trying to talk to a theist-shaped brick wall. The matter of discussion? Why belief that the possibility of extraterrestrial life is more rational than the belief in god.
Now, let me be clear - I'm not talking UFOs coming to kidnap Elvis. I mean extraterrestrial life - bacteria, simple organisms. Yes, I find the possibility of more complex life (plants/animals) likely, even that of sentience, but harder and harder to find the higher up that chain we go. (And certainly not *touching* the whole flying saucers somehow bypassing the incredible distances and happening to find us, etc.)
My point was not even that of proving life - I know there are meteorites from Mars that seem to have fossilized microscopic life or proto-life in them, but from my understanding, scientists are still cautious about calling it "life." My whole point was to show how weight of evidence makes a hypothesis (life exists elsewhere) more credible.
And I thought I had done fairly well. I can't say I did full justice to the subject - I'm not an astrophysicist, chemist or biologist. I have a somewhat-better-than-layperson understanding of the subjects, I think, though not the level of someone actively studying them.
Maybe I was too cautious, but I felt that was the most intellectually honest way to approach it... of course, I'm being intellectually honest, which when trying to get someone to see around their faith, well... they're not.
For instance, I point out that we've explored a very small section of the sky and found many planets - and that the ones we find are getting smaller, meaning we can detect more. That we can figure out what the habitable zone of a star would be and if a detected planet is in it. That we are made from primarily four of the five most common elements in the universe (the fifth being nonreactive,) and that we understand the chemistry and processes of life. (Medicine, for one, wouldn't work if we didn't!) That (in reaction to one of his horribly wrong points, where there's no liquid water elsewhere) we've seen flows on mars (which he calls erosion - no, not the ones with a decided liquid character,) that the Phoenix rover saw drops of liquid water, that Europa gets fresh ice deposited from within (so we've got flowing ice at the least, it seems, and it's suspected of having water) - that water itself is fairly common.
As I'm throwing all these arguments out, I'm getting... I believe the scientific term is crazy shit back. That "God created life only on Earth." Which is utterly illogical - I pointed out that it's like looking at the tree outside your window and concluding it's the only tree on Earth. Not likely. Could it be true? Sure. It's a non-zero possibility... but given the size just of the galaxy, not to mention thinking of the local group or the universe as a whole, I'd have to say excessively unlikely.
In addition, aside from his "proof" being "God did it," nothing I put out there as far as reason why I hold the views I do is good enough.
And as I'm arguing, I'm realizing he's trying, consciously or not, to keep me on the defensive to keep from having to come up with anything to prove his belief in the existance of any deity.
So, if he answers... yeah, I'm going to bring that up. He's already thrown the "I don't have to give any proof!" once. I'm curious if he'll do it again. I just have to wonder if it's a sign of something inside that just doesn't WANT to face the fact that this belief is really untenable once you start looking at it.
Or if he's really just batshit crazy...