Archive for the 'logic' Category

Applying Logic to Creationism / Evolution

A little while ago, and for no apparent reason (I’m like that :) ), I thought about an Internet poll I’ve seen some time ago, which asked people what they thought was more likely about the development of life on Earth. If I remember correctly, the options were something like this:

  1. God created the species as they are, less than 10,000 years ago (young earth creationism);
  2. God created the species as they are, millions of years ago (old earth creationism);
  3. God created life and directed evolution, starting millions of years ago (theistic evolution);
  4. Life evolved without action from a god (natural evolution).

And it got me thinking…

We can think of the several hypotheses as a series of switches. God (as in “interfering”, not as in “existing”)? Yes or no. Old Earth? Yes or no. Evolution? Yes or no. With these switches, here are the 8 possible combinations (with 0 for “no” and 1 for “yes” — yes, I’m a computer geek. :) ):

God? Old Earth? Evolution?
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1

This is the initial premise. But we can quickly remove a few contradictory combinations. For instance, no God and no evolution means that nothing accounts for the life we have in the world today. In other words, we can’t have a “0″ for both God and evolution. Evolution but no old earth is also impossible: nobody — scientists or creationists — claims that species could have evolved in just a couple of millennia, and both sides agree that man already existed 6,000 years ago. In binary terms, evolution requires an old earth (not the other way around, though).

So, the cut-down table (now with labels for each combination) amounts to this:

  God? Old Earth? Evolution?
A 0 1 1
B 1 0 0
C 1 1 0
D 1 1 1

What more can we say about them? Well, for a start: evidence contradicts B and C, so they cannot be true. There is lots of evidence for both evolution and an old earth, and both are accepted by science — not dogmatically, not on authority, but because that’s where the evidence leads. The only reason people still claim B or C is this: it’s what the holy books claim. If you believe they are inerrant, then any evidence to the contrary must be ignored, like covering your ears with your hands and crying “la la la, I can’t hear you”. Of course, such a position is irrational, dishonest, and stupid. Creationism (old earth or young earth) is the denial of reality; it’s not a scientific hypothesis with any merit, because no evidence supports it, and a lot of evidence contradicts it. I can respect people who are honestly mistaken, but not those who lie to themselves, who deny reality, just because it’s somehow uncomfortable or contradicts dogma.

So, if we care the least bit about reality, we must remove any combination with Old Earth=0 or Evolution=0. Therefore, the only remaining combinations are these (keeping the labels from the previous table):

  God? Old Earth? Evolution?
A 0 1 1
D 1 1 1

Now, D is obviously theistic evolution, that is, evolution directed by God. This is undisprovable, because it doesn’t contradict the evidence (but, then again, Last Thursdayism, the theory that the universe was created last Thursday, but with everyone having memories of a fictional time before that, and with the world having been created to appear much older, is also undisprovable). There is, however, no evidence for it, either.

A is not necessarily atheistic naturalism; as I said before, “God” here means intervention by God, not just existence. A can be naturalism, but it can also be Deism. Again, it can’t be disproved, and, again, there is no evidence of “no (intervening) God”. The main difference between A and D is that D adds another agent, which is not required, as A has the exact same evidence for and against it, and explains everything just as well. If both explanations are equally satisfactory and substantiated, but one of them has an extra entity, then Occam’s Razor tells us that the other one — with the least number of entities — is the most likely one. Entities should not be multiplied beyond necessity, and the extra entity is unnecessary.

From this, we arrive at A as the most likely hypothesis. All available evidence agrees with it, and it is the simpler (in terms of number of entities) explanation.

First Causes and Special Pleading

A: Nothing can exist without a cause. The universe exists; what caused it? I say it was God!

B: OK, who caused God, then?

A: Nothing. God wasn’t caused or created; he always existed.

B: Then why can’t the universe have always existed?

A: That’s impossible, nothing can exist without a cause…

Sounds familiar, doesn’t it? :)

This is one of the most common examples of a fallacy called special pleading, that is, introducing an exception to a rule without justifying or proving that exception. Believers postulate God’s existance due to the fact that, according to them, everything needs a cause, or a creator, or a designer. Then what caused, created or designed God in the first place? Ah, that’s an exception. God always was. Why? Just because! And so on.

Unfortunately, arguing with someone who makes a claim like this and doesn’t see a problem with it is typically useless. We’re talking about a person who already “has” the answers, and will ignore any facts or logic contradicting them. You can’t argue with someone who sees no relation between truth and reality.

Fortunately, many believers aren’t like this, and would not use the argument above as proof of their god’s existence. Unfortunately, then we run into another problem: the more a believer is sophisticated and educated, the more he gets away from the absurd, Ray Comfort-like “proofs of God” (a banana?!? seriously…), and the closer he gets to admitting that he has no proofs or evidence at all, just faith… and if he still sees no problem with it, if he sees faith (complete disregard for facts and reality) as a virtue, then, again, there’s nothing that can be done for that believer.

More on the Dawkins / Hitchens / Dennett / Harris discussion (part 2): the immaturity of religious arguments

Hitchens and Dennett

 

Like before, just click on the picture above to go to the source, download or watch the 2-hour video, and so on.

Also like before, I’m going to post and comment on one of my favorite parts of the discussion between the “four horsemen of atheism”.

Daniel Dennett: Right. And you know this, what you just said Christopher, actually, I think, strikes terror, it strikes anxiety, in a lot of religious hearts. Because it just hasn’t been brought home to them that this move of theirs is just off-limits. It’s not the game. You can’t do that. And they’ve been taught all their lives that you can do that - this is a legitimate way of conducting a discussion. And here, suddenly we’re just telling them “I’m sorry, that is not a move in this game”. In fact it is a disqualifying move.

[..]

Christopher Hitchens: Adumbrate the move for me a bit, if you would, or for us. Perhaps only for me. Say what you think that move is.

Dennett: Somebody plays the faith card.

Hitchens: Yes.

Dennett: They say look, I am a Christian and we Christians, we just have to believe this and that’s it. At which point, I guess the polite way of saying it is well, okay, if that’s true you’ll just have to excuse yourself from the discussion because you’ve declared yourself incompetent to proceed with an open mind. Now…

Hitchens: That’s what I hoped. That’s what I hoped you were saying.

Dennett: …if you really can’t defend your view, then sorry, you can’t put it forward. We’re not going to let you play the faith card. Now if you want to defend what your holy book says, in terms that we can appreciate, fine. But because it says it in the holy book, that just doesn’t cut any ice at all. And if you think it does, that’s just arrogant. It is a bullying move and we’re just not going to accept it.

Sam Harris: And it’s a move that they don’t accept when done in the name of another faith.

Dennett: Exactly.

In other words: saying “we just have to believe it and that’s it” is not a rational argument, or a grown-up argument. Nor is saying “it is true, because it says so in my holy book”. Those are appeals to emotion or to authority, which are childish arguments that have no place in an adult, rational discussion… and which believers wouldn’t accept from believers of other faiths, anyway. Those arguments are the equivalent of a child’s “but I wannaaaaaa!!!!”. They only “work” because religion and religious beliefs are still unnaturally and unjustifiably respected.

Incidentally, Dennett’s “Now if you want to defend what your holy book says, in terms that we can appreciate, fine” reminds me of Barack Obama’s “Democracy demands that the religiously motivated translate their concerns into universal, rather than religion-specific, values. It requires that their proposals be subject to argument, and amenable to reason. I may be opposed to abortion for religious reasons, but if I seek to pass a law banning the practice, I cannot simply point to the teachings of my church or evoke God’s will. I have to explain why abortion violates some principle that is accessible to people of all faiths, including those with no faith at all”.

In other words — and even though Obama is himself a Christian — both are saying that childish arguments, such as appeals to authority or emotions, just won’t do in real life. This is probably shocking to many believers, who are used to, and comfortable with, their immaturity of beliefs and arguments. It probably explains why Christians cry “we’re being oppressed!” merely for not being allowed to oppress others anymore… after all, they’re suddenly losing a right privilege they’ve had for centuries, when they were so powerful that they were able to act like spoiled children, both in terms of arguments and of actions. Suddenly being told to grow up and act like adults — for the first time in centuries — probably feels like “oppression” to them…

The "one in a million" fallacy

This is the first of a couple of posts dealing with No Way’s comment on my previous post. This one doesn’t deal with religion / atheism at all, so it may be refreshing for a change. :) The next one does, though.

This one concerns this: the argument that the combination of conditions necessary for life is incredibly rare, so such a result could never happen by chance. This is, of course, logically flawed, and is related to the gambler’s fallacy.

Consider the following example: get a bunch of normal, 6-sided dice. Roll one; the odds of getting a six are, of course, 1 in 6.

If you roll two, the odds of getting “66″ are 1 in 6×6, or 1 in 36. The chances of getting “666″ are 1 in 216. And so on.

If you roll twenty dice, the chances of getting all sixes, or “66666666666666666666″, are 1 in 3656158440062976. Virtually impossible, right? You’d virtually never, ever get all 20 sixes at a try, even if you spent the rest of your life throwing dice. A “random-looking” result such as “31423461534212543212″ is much more likely, right?

Nope. “31423461534212543212″, or any other particular result, is exactly as likely as “66666666666666666666″. If you were betting on a result, it would make as much sense to bet on one as on the other.

The consequence of that is the following: after you get a randomly achieved result — any result! — you can then look at it and say that the odds of getting that result are fantastically small… so small that it “surely” took a miracle to have arrived at it!

The problem is that it works for any result whatsoever. Like in the previous example: roll 20 dice, and the odds of getting that exact result are, as I said, 1 in 3656158440062976. Sounds virtually impossible, right? Yet, you’ve just arrived at it… by pure chance.

The argument from design adds a variation to the above, though, but that’s a matter for the next post, since I promised that this one would be religion/atheism-free. :)

"Circular Logic R Us"

Bible

Isn’t it annoying when Christians use the Bible as “proof” that God exists?

Yesterday, I had to delete several comments here, all from the same guy. They were long and obviously written long before, totally unrelated to the posts they appeared on, and most of them were quotes from the Bible, including, repeated several times, a bit from a psalm: “The fool says in his heart, “There is no God.”" Obviously, that was supposed to convince me, and any other atheists, that we’re being utter fools by disbelieving God… since the Bible says only fools do so!

Christians, if you don’t see the problem with that “logic”, anything I say will probably fall on deaf ears anyway… but, please, think just a little about it.

Suppose I write a book tomorrow, and in that book I write that I am God. Would you believe it, because that book says I’m God, and, so, since I wrote it, that book is the word of God, and therefore it must be true?

I’m sure you won’t. “A says B is true, and B says A is true, which proves both are true” is circular logic, and it doesn’t work.

Well, it’s exactly the same thing with your book. We think of it as you think of the Qur’an: not a reliable source. Do you believe Muhammad’s claims are true just because the Qur’an — which he wrote — says so?

Anyone (who is literate, that is) can write a book. And, sorry to say, yours isn’t special.

"True atheists" and redefining words

On Bligbi, there is a recent post called On true atheists, about the fact that some “atheists” attempt to set what “true atheists” must be like.

I agree with KC on this, of course; atheism is simply the lack of belief in gods, nothing more. To say “you are not a true atheist” for any reason other than “well, you do believe in a god” is an obvious example of the No true Scotsman fallacy.

It is, indeed, something I’ve mentioned in the past: how some people, for varied reasons, redefine words to mean something other than the accepted definintion, up to a point where you can’t have a useful conversation with them.

Some do it to escape from a negative association. E.g. “yes, the Inquisition was horrible, but those were not true Christians.”

Others, like the ones mentioned in the Bligbi post, do so to make the term fit with their own view. “I consider myself an atheist, and I like X, therefore true atheists must also like X.”

And some people are weirder. :) They make something up, but are not self-confident enough to admit their own originality, so they “steal” an accepted term and use it for what they just came up with. For instance, inventing a really weird set of beliefs — today — and calling it “Christianity”. For bonus points, say that it’s the only “true” Christianity, and that people have been wrong (see, Jesus was actually an alien, and to be saved you must worship pink things… while standing on one foot) for 2000 years. :)

FAQ: How can you be an atheist? You can’t prove God doesn’t exist!

I can reply to that question in two ways, and either of them is enough.

1- I don’t have to.

You’ve probably heard the term “burden of proof” before. In this context, it works like this: when someone makes a new claim, it’s his responsibility to prove it, or at least provide some evidence for it, instead of someone else having to disprove it. In other words, the burden of proof is on the side of those who make the claim — especially if it’s a bold or uncommon one.

Imagine someone accuses you of being an alien disguised as a human. Would you feel that you have an obligation to prove that you’re a real human? Of course not. It’s the other person who has to provide evidence for their claims.

It works that way, too, for claims like “there is a god, and he’s exactly like I believe he is”. The one who makes the claim has the burden of proof. A question such as “can you prove that it didn’t happen?” only works in Ed Wood movies. :)

2- Can you prove X doesn’t exist, then?

Another way to counter the “you can’t prove God doesn’t exist” claim is to ask the same question back at you. Can you prove Zeus doesn’t exist? Aphrodite? Odin? Thor? Allah? Kali? Nanabozho?

You’ll have to admit that you can’t. In fact, you could dedicate the rest of your life to proving that any of them doesn’t exist, and you’d fail miserably. I’ll assume, then, that you believe all of them are likely to exist, right?

No? Why not, then? Believing in one god because you can’t prove he doesn’t exist, but not applying the same logic to all the other gods, is a classic example of a double standard. But I bet that you’re applying the “you can’t prove he doesn’t exist” logic to your god only…

(Note: please keep any comments related to the above question / answer, and not to other subjects, such as whether God exists or not. Thanks.)

Thinking about the liar paradox…

Changing the topic into something lighter than metaphysics…

Are you familiar with the liar paradox? There are several variations of it, but the most common is probably this:

The next sentence is false. The previous sentence is true.

Now, if sentence 1 is true, then 2 must be false, which means that sentence 1 isn’t true after all… but then it means that 2 must be true… and so on. It’s impossible to solve; it’s a paradox.

An even simpler version is the following:

This sentence is false.

Now, is it true or false? :)

Finally, let’s consider a third case:

Everything I say is false.

My question is: is this the liar paradox again? Or is it actually possible, and not a paradox at all?

If you’re reading this on the front page, you’ll have to click on “Continue reading…” for the answer. If you’re using your feed reader, or Planet Atheism, or arrived directly at this post, the answer is below, so… close your eyes now and think about it before you open them again. :)

Continue reading ‘Thinking about the liar paradox…’

Accepting the opposing viewpoint for the sake of argument

On the previous post, I quoted Ebon Musings, and one of the quoted parts was the following:

Consider honestly the possibility that you might be wrong, accept the opposing viewpoint for the sake of argument, and then ask yourself: Does the evidence make more sense from this perspective? Is the world I live in the one I would expect to see if this hypothesis is true, or is this the world I would expect under its negation?

I believe that part is so important that it deserves a post of its own. :)

Now, answer me honestly: how often do you do the above? How many times in your life have you stopped to consider an opposing point of view, an opposing theory, hypothesis, or explanation, and actually thought about whether it better explains the universe around you? Whether it is simpler, and you need to come up with fewer rationalizations or exceptions of your own?

Though this is certainly not related just to religion (we could easily apply it to politics, for instance), consider the following example: young earth creationism.

A young earth creationist (YEC), these days, has a lot of explaining to do. He believes in the Bible, literally; to him, it’s, by definition, the absolute truth. Therefore, anything that happens differently, must either be ignored, or explained somehow.

If you know YECs, how many times have you heard “explanations” such as:

  • “God made the fossils appear much older to scientific tests in order to test our faith.”
  • “When God created the stars, he made it so that the light from them was already arriving at the Earth, and so they appear much older.”

… and so on?

Now, do you believe that an YEC has actually, ever, stopped to think about the opposing point of view? And, sincerely, wondered if that other explanation doesn’t fit reality around him much better, and without the need for so many excuses, exceptions, explanations, and so on? Whether - frighteningly enough - “the other side” might actually be on to something?

I doubt it. :(

As I said, this doesn’t apply just to religion. There are many times when we should stop for a minute and consider “the other side”’s position, just to see if it fits with what you see. Stop demonizing your opponent for a moment, and think about his reasons for his viewpoint. You may find out that you’re right… or that you’re wrong. Either way, you learn and improve.

It’s a rare “skill”, though…

"Closed minds"

Unless you’re some kind of religious fundamentalist, it’s likely that you will agree that an open mind is a positive quality. And, when arguing, both you and your opponents should be on guard against having a closed mind, that is, refusing to even consider the possibility that you are wrong.

However, some people - I see this from time to time - use the “you don’t have an open mind!” argument in a very peculiar way…

It goes like this:

Person A: “2 plus 2 equals 4.”

Person B: “That’s very closed-minded. You’re not even considering the possibility that you’re wrong, and that 2 + 2 equals something other than 4. You refuse to listen to any opinions or ideas different from your own. Other people may believe that 2 + 2 equals, say, 5, and who’s to say that you know better than them? How can you be so arrogantly sure? You talk about keeping an open mind, and yet you accept on faith than 2 + 2 equals 4, and refuse to think further about it. That’s dogmatic, like any religion.”

<sigh>

Yes, relativism is a terrible thing - it denies the existence of facts, of an objective reality. To a relativist, there are no facts, only opinions, and there’s nothing that says that one is better or truer than another. A relativist prides himself on “an open mind”, because, after all, he’s prepared to believe anything and everything, without judging, without using his mind at all.

However, that attitude is nothing more than a refusal to think and to deal with an objective reality on its terms. It’s pure cowardice - reality is scary, so you deny it.

An open mind does not mean denying the existence of facts. That’s just an absurd distortion of the concept.

Wikipedia: the Omnipotence Paradox

Today’s featured article on Wikipedia is the Omnipotence Paradox. In short, it’s this: can an omnipotent being (say, the Christian god) create a rock so heavy that he himself can’t lift it?

The argument goes like this: if he can, then he isn’t really omnipotent. If he can’t, then he isn’t really omnipotent.

Of course, it isn’t so simple, and that’s why this has been discussed for centuries - and I’m guessing that some people through history have been burned for heresy for asking this question.

Read the article, it’s very detailed and includes many different “answers” to the paradox.




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