Monday, June 19, 2017

Evidence and fine tuning

Evidence, at least to me, would be a fact of experience that is more likely to exist if there is a God than if there is no God. Even if the such facts are outweighed by other facts, isn't it pretty cleat that such facts exist? One of them would be the fine-tuning of the universe, the fact that only because the universe began with cosmic constants that fall within some very narrow specifications did life emerge. We might have discovered the life could have emerged on many possible initial cosmic constants, but we didn't discover this. 

14 comments:

Hugo Pelland said...

The so-called fine tuning shows our ability to measure these constants with great degree of precision more than anything else. It does not follow that these are the only possible values, nor that they are unlikely. In our universe, just a tiny tiny change would prevent atoms from forming or stars from burning, etc.. but that means nothing when it comes to interpreting them as being special, somehow. It's very easy to come up with possible scenarios that explain these values and the design argument thus fail, given that the design argument rests on the fact that there are no other possible option. Unless I misunderstand the argument but I have not heard a better defense...

David Brightly said...

Yup. On the scientific picture we have to conceive that an extremely improbable event occurred---though it's hard to say what probability could mean when we are talking about the origin of space, time, and everything that is. On the religious picture we have to conceive of something thinking and acting outside of space and time altogether. Some dilemma!

Aron Zavaro said...

Victor,

How do you respond to the claim that P(FT|~G) is neither low nor high, but rather it is meaningless to discuss probabilities in this context because it is mathematically meaningless to talk about a flat probability distribution over an infinite range?

I've heard the responses of Collins, Pruss, Barnes, and Plantinga, and so far I have been unimpressed.

Mortal said...

Although I personally believe fine tuning to be the work of the Creator, I do not think it makes for a good argument. There are simply too many counter arguments, such as:

- The way things are, is the only way things can be (sort of like, two plus two can only equal four).
- There are an infinite number of universes, and we happen to be in the one with the various constraints allowing for us to exist (the multiverse concept).
- There's nothing remarkable about fine tuning (the ol' "Why should we be surprised if the water in a rain puddle matches the contours of its depression exactly?" line of reasoning).
- etc.

Victor Reppert said...

In this context, I am bringing this up in response to the no-evidence charge. It seems to me that if you were completely 50-50 on God, and you became aware of fine-tuning, this should swing you to the theist side. Therefore, it is, to my mind, a good refutation of the no-evidence charge. If we are atheists, and we haven't discovered it already, we should expect the scientific evidence to point away from fine-tuning. If we are theists, this is what we should expect.

But I am also someone who thinks that the argument from evil provides some evidence for atheism.

I think the only hope for the no-evidence claim is if you make the argument that God is not the kind of thing for which evidence is possible. This is the Steve Zara-P. Z. Myers position that Dawkins has now accepted. The idea that there can be evidence for God, but we don't have it, strikes me as a nonstarter.

Aron Zavaro said...

In order for fine tuning to count as evidence, we need to be able to say that P(FT|~atheism) has a value between 0 and 1. But the McGrews have forcefully argued that this is mathematically impossible

Hugo Pelland said...

Victor,
"and you became aware of fine-tuning, this should swing you to the theist side.
...
we should expect the scientific evidence to point away from fine-tuning. If we are theists, this is what we should expect"

Why? Why expect fine tuned values, or not?

We can even make an argument for exactly the opposite: if the universe were designed, the constant wouldn't need to be fine tuned; a clever designer would make sure that their creation works reliably and thus not subject to failure because of small variation. Hence, the universe was not designed...?

Of course that doesn't really prove anything, and that's the point.

Victor Reppert said...

We can even make an argument for exactly the opposite: if the universe were designed, the constant wouldn't need to be fine tuned; a clever designer would make sure that their creation works reliably and thus not subject to failure because of small variation.

Why would he want to?

Hugo Pelland said...

Bingo, why would he? Or why not? We don't know. You just disproved the argument.

grodrigues said...

@Mortal:

"There are simply too many counter arguments, such as:"

While like you, I do not think much of the fine-tuning argument, I think even less of the counter-arguments you list.

I have recently became acutely aware of this curious phenomenon: arguments from theists that are weak, but where the weaknesses are best exposed by other theists, the atheist counter-arguments being even worse than the original arguments.

Aron Zavaro said...

A lot of different pieces of data are being clumped together here. Let's separate them:

L=life exists
S=the laws of physics are strict rather than lenient - i.e., they are such that only a small range of values for the constants are compatible with life naturally existing
N=life exists naturally - i.e., the values of the constants fall in the life permitting range, and therefore the existence of life is not in violation of the laws of physics

T is theism and A is atheism

P(L|T)>P(L|A) because God would have reasons to want life, whereas the universe is indifferent, so L is evidence for God, if not big evidence

P(N|T&L)<P(N|A&L) because given that life exists, atheism entails that it must exist naturally (consistent with all natural laws), but on theism, life can exist in ways that are not consistent with natural laws, because a God can do miracles, so N is evidence for atheism, if not huge evidence

P(S|N&L&T)=P(S|N&L&A) because L&N screen off S from T and A. Imagine a spectrum with the most strict possible laws on the left and the most lenient possible laws on the right. Along the spectrum are dots representing universes in which life is naturally permitted. Obviously, there will be more dots on the right side of the spectrum. Given that we know our universe is one with L&N, our universe must be one of the dots on the spectrum. And because there are an equal number of dots located on the S side of the spectrum, regardless of whether theism or atheism is true. So given N&L, the likelihood of S is the same, regardless of whether T or A is true. For both atheism and theism, the likelihood of S being true will necessarily just be (dots representing strict law universes / total dots). This point has been demonstrated by Jonathan Weisberg.

So life is some evidence for God. The fact that life exists in a way compatible with natural laws is some evidence for atheism. And the strictness of the laws of physics is not evidence for either.

Mortal said...

grodrigues,

Well, I didn't say they were good counter-arguments, but they do seem to satisfy those who use them.

A actually think the first one is solid, while the multiverse idea is junk science, and the third argument is a variation of "brute fact" reasoning, sort of like answering a question with "Just because!"

But even if we granted that there was no possibility for our universe to be anything other than what it is, that still does not rule out design. I'd say the idea is neutral to the debate. (I am aware that an atheist might conclude otherwise.)

grodrigues said...

@Mortal:

"Well, I didn't say they were good counter-arguments, but they do seem to satisfy those who use them."

I confess I am only interested in whether the arguments are good or not, not in whether someone is "satisfied" by them. That fact only tells us about the person, not the argument.

"A actually think the first one is solid"

There isn't a single half-decent argument for it, not one -- I do not count sheer assertion, question begging or changing the topic as good arguments.

Stardusty Psyche said...

Victor Reppert said...

" We can even make an argument for exactly the opposite: if the universe were designed, the constant wouldn't need to be fine tuned; a clever designer would make sure that their creation works reliably and thus not subject to failure because of small variation.
Why would he want to?"
--Then who is this clever designer that fine tuned god? God's god?

Perhaps you say god just always existed. Ok, so something extremely complicated and powerful can just exist from negative infinity. In that case, why bother with the god speculation at all?

Perhaps you say god is not fine tuned. So any old sort of existence can make up a god?

The god hypothesis solves nothing, explains nothing, and only makes the problem more difficult.


June 20, 2017 7:04 PM