"We can't logically show that there is an outside word or that the sun will rise tomorrow..."
Posted on: November 15, 2007 - 8:00pm

"We can't logically show that there is an outside word or that the sun will rise tomorrow..."
"We can't logically show that there is an outside word or that the sun will rise tomorrow..."
I came across this statement recently. What logical fallacy is it making? It seems to be arguing from inductive uncertainty, although for this fallacy to apply does it require the person to go on to reject the proposition, rather than simply saying it cannot be logically proven.
The same person also wrote the following:
Quote:
My skepticism is not of the outside world, but of the role of logic in finding truth. At the most fundamental level, the outside world existing is logically no more justifiable than God's existence. That doesn't mean that they are equally true, or that an intelligent person should conclude that they are equally true. In deciding which is true, however, we must rely on our intuition and instincts, although that is not to say we should not think carefully about the matter. Even if I say that Christians have "the burden of proof" and that "occam's razor disproves creation", I am not really pointing to something I know to be logically true, but really to something that I feel intuitively to be true.
There seems something wrong about that line of thinking. It seems to imply that we ultimatly rely on our intuitiion/instincts.

































On the surface, it looks like he's going for the Transcendental Argument for God (TAG) which starts at the problem of induction, and proceeds into non-sequitur fairly quickly. I think it is a basis for the presuppositionalist position. This was posed formally in these forums by nerd Kelly Tripplehorn, in his "Stanford Challenge" (which was later renamed the "Van Til Challenge" when Stanford asked to be left out of it).
Here's a version of the argument being posed by a washed up musician:
http://www.youtube.com/watch?v=NO5mnif4lsg
Here are several videos regarding it:
http://www.youtube.com/watch?v=FbJxqE5Z1NQ
http://www.youtube.com/watch?v=DqG_gwEH7Qg
http://www.youtube.com/watch?v=XwIEYiknXzU
Here are a couple of videos from todangst on the subject:
http://www.youtube.com/watch?v=DbxbFvaAGuA
http://www.youtube.com/watch?v=R-P_6c46wxQ
"We don't have to justify the things that don't make any sense anymore."
~former Scientologist Greg Barnes
xenutv.com
Interestingly the person who I quoted is an atheist.
'Supernatural' (and 'immaterial' ) are broken concepts
- Submitted by todangst
A better explaination of this is here:
Why the "Problem of Induction" really isn't a problem. (And why theists don't even get it right)
Also submitted by todangst
I'm atheist
Look to David Hume and Enquiry Concerning Human Understanding. In Books 3 and 4, he explains causation and the fact that it is not extant. He then tells about the problem with induction. Hope it helps.
"Tis better to rule in Hell than to serve in Heaven." -Lucifer
"...there is nothing illogical or irrational about assuming that induction works, nor are there any rational grounds for holding that 'induction is untrustworthy'. The fact that I cannot be absolutely certain that the sun will rise tomorrow does not give me any justification in holding that it will not rise tomorrow..."
I'm atheist
Sorry, I don't know how to delete my comments.
It seems that Laplace's Rule of Succession asssumes that the probability of an event happening in the future is the same as at any point in the past, thus allowing him to infer from the frequency of events happening in the past, the likelihood of events happening in the future. The problem of induction is that we cannot know that they will behave with the same probabilities, so Laplace's Rule of Succession cannot be used to solve it.
There are neither any logical grounds for supposing that induction does or doesn't work. While logic does not say we shouldn't believe in induction, it doesn't say that we should either. That choice is not one we make a rational decision about.
Laplace does not apply frequentist probability. He applies Bayesian probability (i.e. subjective probability).
http://en.wikipedia.org/wiki/Rule_of_succession:
'...This must not be interpreted to mean that in 30% of all cases, p is between 20% and 50%; that would be a frequentist philosophy of applied probability. Rather, it means that one's state of knowledge (or ignorance) justifies one in being 30% sure that the sun rises between 20% of the time and 50% of the time -- that is a Bayesian philosophy of applied probability."
"We are a way for the Cosmos to know itself." -- Carl Sagan
Yes. The probability that he obtains is not a frequentist probability, although it is similar. He makes the assumption that the probability of an event happening is the same in the future as the past. From this he uses Bayes' Theorem to deduce the probability of, say, a special coin landing on heads even though it has landed on tails the previous 30 times.
For instance, look at this problem. There are two outcomes for an event, and the probability of either outcome is between 0 and 1. Now lets say we repeat the event 99 times and only one outcome (A) is observed. Do you say that the probability that the next time the event is repeated the probability of A being the outcome is 1? No, because we cannot know that. If the probability of outcome B was 0.001 for each time the event happens, it would not be that surprising at all that we've only seen outcome A. We can't say the probability is 0.01 either, as that would be a frequentist probability based on the assumption that the next outcome will be B, which is obviously very wrong. What Laplace does is use Bayes' Theorem to calculate the probability of the next event being A or B. Note that at no point is the problem of induction solved. The whole solution is based on the assumption that the probability that A will happen is the same every time the event happens.
What do you believe the justification for his rule to be? How do you believe this circumvents the problem of induction?
I'm atheist
Argument from inductive uncertainty is not automatically a fallacy in all cases. Inductive uncertainty is a fact of logic that we can usually ignore, but it never actually goes away.
"After Jesus was born, the Old Testament basically became a way for Bible publishers to keep their word count up." -Stephen Colbert
Topher seems to be the RRS agent for recruiting posters from MAP!
Welcome to RRS LJoll.
I think that there is an argument for induction based on bayesian probability.
Say that we see A coincide with B in a certain way (causation for example?)
We then predict that next time A occurs, B will relate in the same way as before.
If our prediction is right, there are two possibilities:
Either there was a genuine relation or it was down to random chance.
The more our prediction is right, the less likely it is to be random chance, so the more likely there is to be a genuine relation between A and B.
For example:
I notice a coin keeps getting heads and suspect that it is biased to land to heads rather than tails.
So I expect flicking the coin to relate to getting heads.
Now I have my prediction, I can continue to toss the coin.
As I get more results, I can use the probability to determine whether the results tend to be even, or whether the coin is seriously biased towards the other.
So I think that conclusions from induction can be logically justified.
I'm fairly certain that the sun will rise tomorrow, but I havent come to that conclusion based on some a priori mathematical proof.
That feels right, but it can't be shown logically. How do you distinghuish between the theory that the odds of a coin landing on heads are always 0.5 from the odds of a coin landing on heads will be 0.5 until april 7th 2026, when they will change to 0.25. The method you have put forward is similar to hypothetical-deductivism that Popper put forward and seems to be common sense solution to the problem, as you are no longer just going from seeing something happening every day, to a universal rule; instead you are making a hypothesis which is backed up by several pieces of evidence which simulaneously disproves other hypotheses. Unfortunately it just approaches the same problem from a different direction, as all the evidence we observe is also evidence of an infinite number of alternate theories.
Yeah, what LJoll said.
And like I said, the problem of induction is not a problem most of the time. It's only a problem when one tries to claim absolute certainty from an inductive argument.
"After Jesus was born, the Old Testament basically became a way for Bible publishers to keep their word count up." -Stephen Colbert
It's not just absolute certainty. You cannot even apply a probability to an inductive argument.
We can't prove there is an outside world and that the sun will rise tomorrow. Hm. Here is what I would say to that person.
We can't prove either one absolutely. This is true. Just because the sun has risen (or the Earth has revolved, however you want to look at it) billions of times before does not necessarily mean it will still do so 72 hours from now.
I can't prove that the outside world is real either. Perhaps everything is just a holographic image until the exact moment that it is observed. But perhaps those observations are lies. How do we know?
To that I would say, you're right, but who really gives a shit? If you tell me that there is no way to know at any moment that the sun will continue to behave the way I expect, I could just as easily ask you to tell me what the sun would then do.
If you tell me that the outside world may not even exist, I would then ask you to explain to me what the "perceived outside world" must be.
Whatever you try to substitute in its place would surely fall victim to the same flawed logic you are accusing me of. The result is a stalemate.
We come to these kinds of inductive conclusions because we must. If I am an animal in the wild and I make the observation that all the red berries I have ever encountered are good to eat, I continue to eat the red berries. Similarly, just because I have always had a mouth and a digestion system to eat and digest berries, doesn't mean that I certainly will tomorrow, but it would be stupid of me to automatically assume, based on that knowledge, that I don't have to eat any berries. Perhaps tomorrow I will wake up as an immortal that has no desire for food, but it would be stupid for me to count on it.
None of this means that my conclusions are right or that my reasoning is valid, but I am hungry, I want to live, and I need to make a decision. I know that I exist. I know that I don't want to cease to exist.
Just because the sun will not necessarily rise tomorrow does not automatically mean that I should stop believing that it will. Just because the outside world may not actually exist or may not be what I think it is (we could all be plugged into the Matrix, after all!), does not automatically mean that I should stop believing that the world is what it is.
We accept the reality of the world we are given (or maybe tomorrow we won't! Where does it end?!?!)
But what else are we going to do?
As for the suggestion that the outside world is no more justifiable than God's existence:
If you're arguing for an unrevealed god, I may let that slide. But if you're arguing for the god of a revealed religion that supposedly created then world, then are you saying that God created a world that we can't prove actually exists, and that's how we know God exists?
Hmm... something about that doesn't work. I'll let you figure that one out.
But if you're saying "some god that we just don't know about", then okay whatever. As long as we both acknowledge that you don't know anything about him and so it's probably pointless for us to even be talking about him, if he exists, which we can't really be sure of.
*sigh*
"What would Jesus do for a Klondike Bar?"
"Faith is a lot like virginity. You can't appreciate how annoying it is until you actually lose it."
I'm atheist
Logically we can't prove that the Sun will rise tomorrow, but that is only an academic point.
We can attempt to set bounds on the probability based on enumerating all the scenarios we can imagine which might prevent it, and estimating their probability from what we currently know of physics and the movement of astronomic objects in our vicinity.
We know it would require a massive amount of energy to stop the Earth from rotating, which is the most intelligible physical event that would lead to such an observation. Extremely unlikely we would survive the impact big enough to create such an effect.
Inductive reasoning is all about estimating probabilities of various alternative explanations.
Speculation about fundamental nature of the Universe changing dramatically at any future point is pointless, since all the evidence we have to date is that it hasn't happened since the earliest instants after the Big Bang.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
"We can't logically prove that the sun will rise tomorrow"
Its a fallacy because he/she is not ignoring inductive uncertainty.
All inductive statements are tentative, and therefore are a bit uncertain. What matters is the amplitude of uncertainty and the relevance to the importance of the precision needed to convey meaning.
It is justifiable to say the sun will rise tomorrow.
I'm atheist
It is not a logical fallacy, the mistake is to think it tells us anything at all useful about anything, except that 99% of philosophy is worse than a waste of time...
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
Thanks BobSpence1, for concluding this crazy rant of sophism, as 2+2 could = 5,6,7, ....
Yeah I could be wrong tho .... on the # 4 ???, .....
All you've done is accept the point and then apply the same point to arguments that no one has even made. Well done.
I just feel that it's true.
I think you've misunderstood the fundamental point. You've said that we can be fairly certain that the fundamental laws of nature won't change because we've observed the fundamental laws remaining unchanged through history. This relies on the assumption the future will look like the past. How can you know that is true? Because it always has been before? That makes the same assumption, so is a circular argument.
You don't understand. How can you even justify a probability for the Sun rising tomorrow? You cannot. I am not arguing that the logical process of induction leaves slight doubt, therefore we have to completely ignore it. I am arguing that induction is completely logiclly unfounded, so you have no excuse to pretend your knowledge is ultimately rational.