you could analyze all the SETI data. you could read everything written about if aliens exist. you could make your own telescopes or rocket ships.
these efforts could take a lifetime or at least more time then you are willing to spend to develop a yes or no answer.
it is also true that if you did do all those actions the result might still be inconclusive.
Technically, the answer is “no” you don’t believe that aliens do exist. You believe there is a strong possibility that aliens might exist, but you aren’t certain that it (their existence) is a fact.
This is a paraphrasing of Penn Jillette’s argument that agnosticism is just atheism in disguise. Belief in an unproven fact is either active or nonexistent. That’s also the rule of logic for mathematics: if it’s not totally true all the time, it’s false.
Tell him that your opinion is not a yes/no question. But what he really is asking is a probability question, and that is math.
Does he like math? If so you could introduce him to the Drake Equation and let him form his own opinion.
If he hates math, tell him he needs to learn it and learn it well to find the answer.
That ought to shut him up.
Tell him to go chop some wood.
You’re confusing two different things here.
My point was that teaching him about abstract concepts and HUGE timespans can help the kid realize just how unlikely it is that we will ever meet aliens. Even if aliens existed, they probably don’t exist right now, in our hairbreadth-wide slice of time.
You could argue the exact opposite: The answer is “No” he doesn’t believe that aliens do not exist. He believes it’s a possibility that they might exist, but he’s not certain that the alien’s non-existence is a fact, either.
Unless the question is phrased a particular way, and it’s clear that the phrasing is deliberate and meaningful, there’s no logical reason to argue either side. The right answer is “I have no belief”, not “yes” or “no”.
Well, OK, but that doesn’t have anything to do with the question about belief in alien existence. Maybe you’re confusing two different things.
Meant to say to the OP, if it was me I’d try and come up with a question that clearly has a factual answer, but he has no way of knowing the answer to, and repeatedly ask him what he believes. Make sure it’s not something he can’t justify a belief one way or the other; for instance, with the ‘what’s in the shoebox’ question, he could say something like “Well, I believe that you’d try and trick me, so, No I don’t believe that there’s a paper in there”.
Maybe flip a coin and cover it before either one of you can see the result. Ask him if he believes it is heads. If he says “Yes” you can start saying “Really? You don’t think there’s a chance it’s tails? Then how can you really believe it is heads?”. The advantage to this is that if he justs walk away without engaging it, but tries to ask you about aliens later, you can just pull another coin out of your pocket and threaten him with it.
“Today I don’t believe aliens exist. Tomorrow, I might”
In other words- you don’t believe they exist. Your belief isn’t dogmatic though and would be swayed by evidence.
If you were a bettin’ man (woman) where would you put your money?
It’s an over under bet. Is the total number of alien (non-Earth) life forms Over or Under 0.5?
It’s a $1 bet, and I’m giving you the dollar from my own pocket, which way do you go?
In terms of evidence, lack of evidence is the only thing that makes an opinion interesting. Once you have actual evidence of other life forms, opinions are irrelevant, it’s like betting after the game’s over.
That’s easy. As long as there is any chance whatsoever of over, even 1%, bet on over.
If reality is under, the bet will never resolve, as we will never be able to prove that none exist. I would never get any money from this bet even if I am correct.
If reality is over, the bet may actually resolve at some point in the future with proof of life elsewhere and I might actually get some money.
Reminds me of Pascal’s Wager.
I’m guessing that this is about making decisions with less than perfect information. He understands you don’t know for sure either way. But there are a lot of things you don’t/can’t know for sure but you still have to decide, or choose a course of action. With aliens, you have the luxury of sitting back and waiting for more evidence, but in a situation where you didn’t, how would you handle that?
all this endless jibber jabber is to make sure the shape shifting aliens haven’t assumed your personage and thrown your body into a volcano.
Have you asked him what he believes? Is it possible there is another kid he knows who is haranguing him for an answer, and he doesn’t know what to say, and is looking for guidance from you? Have you asked him why he wants to know? maybe what he really wants to know is whether it is possible that aliens have ever landed on earth-- he may be frightened by something he saw on TV, or something another kid told him. If you tell him that ypou don’t know whether life exists on another planet or not, but you are certain it has never visited earth (assuming that is the case-- I don’t want to put words in your mouth), that may be what he really wants to hear.
If this seems to have come out of nowhere, is as persistent as you say, and is not his usual way of thinking, I suspect a backstory. Get that story, and you will get to his real question.
Tell him “okay I believe in aliens, and I want to draw one. What do I draw?”
Then
“Let’s say I don’t believe in aliens. We can start to name all the stars, help me in explaining why I don’t believe in an alien around that star.”
In other words, give both answers and help him explore the consequences of the answer - which will be unsatisfactory. Maybe that will help.
If the kid’s name is Erwin, he might respond, “I believe the both is and is not a piece of paper with ‘aliens’ on it in the box.”
He’s not asking if there ARE aliens out there. He’s asking if you believe that there are. So, yeah, you don’t know. But do you believe there are or not? My suggestion is, say yes or no.
See, this is part of the attitude I was complaining about. It’s impossible for every person to have formed a belief about every issue. It’s entirely reasonable to say “I don’t know what to believe” and to leave it at that. Instead, we get tricked into this idea that we need to take a position… and then, having taken a position we feel a need to dig our heels in to defend it. (And then, when all is said and done, we’ve ruined Thanksgiving debating an issue that none of us know the first thing about. 
)
I really think people need change their attitudes about “I don’t know.” Sometimes, that’s the most wise answer you can give.
Just tell him that of course aliens exist and indeed there have been a number of alien abductions in your neighbourhood.
Apparently they come into your bedroom at night and perform surgery on you while you lie there, paralyzed. And they prefer young bodies to analyze, natch.