Inverse Probability and the Argument from Design

Atheistextremist
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Inverse Probability and the Argument from Design

When we look at the universe with the laws of governance that give some structure it’s possible to wonder if this structure is the result of design undertaken by some power of some sort that could be described as a type of god.

We have a premise – P – that the universe shows a sort of design. And we have a conclusion – C – that asserts the existence of a creator.

What this means is that unless C is true, P is unlikely, and in the case of P, C seems likely.

But what we really need to do in order to discover if P is a strong inductive reason for C, is to work out the probability that C,  given P, is greater than its negation.

The high probability of P given C, does not mean there’s a high probability of C, given P.

We’re talking about inverse probabilities and if the Argument from Design is to function, the probability of C given P must be higher than its negation.

Before we go on, let’s look at a simple example. Say for instance we are trying to work out which day of the year it is. Let’s say we think it might be the 164th day of the year. What are the chances this is correct? The chances are much higher it is any one of the other possible 365 days of the year.

Taking this example to the Argument from Design we can see there are many different ways the universe could have been – some might have had a law of gravity that repelled for instance. The possibilities of different applications and reversals of laws known and unknown are endless. These disordered universal possibilities allow us to say the level of order we see is a special property but all those other possibilities suggest there are relatively few universes in which there is likely to be a creator. Not all possible universes are special and creators must be more special still.

This suggest a priori, that C is far less likely than it is likely. The Argument From Design fails and its subscribers can be said to be confusing probabilities with inverse probabilities.

Acknowledgment: Graham Priest.

"Experiments are the only means of knowledge at our disposal. The rest is poetry, imagination." Max Planck

Teralek
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This is rather confusing...

This is rather confusing... but it implies the existence of more Universes than this one. The existence of which is highly speculative and act as the Einstein cosmological constant did for his theory - Multiverse was put on the equation to explain reality without calling God... It would be much more simple if the Universe hadn't begun...

Atheistextremist
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Yeah I don't love

The point Priest is making with this bit of logic but I think the idea is that if the godly say we live in universe that appears designed, then you have to ask them, designed in comparison to what? Compared to all those possible universes that don't show evidence of design.

This universe can't be described by theists as 'special' if there are no other universes that aren't special. Of course, this could just be the way all universes must be. I know we can't really speculate too usefully on the existence of universes outside this universe but that applies to gods who exist outside the universe, too.

"Experiments are the only means of knowledge at our disposal. The rest is poetry, imagination." Max Planck

Teralek
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I see... but I don't think

I see... but I don't think your reasoning adds up. Many scientists like Hubert Reeves, which I much enjoy reading, amaze themselfs with the narrow conditions this Universe possesses. Not only conditions but coincidences as he puts it. Without which we could not have existed. The Universe shows a design pattern which allows for complex molecules to form.

As you put it, it shows design compared to other theoretical Universes that could have existed. This in no way proves the existence of God. If there is a random process that keeps creating Universes with different conditions, then probably a God does not exist. If there is just this Universe we would have to ask why it is as such... and this is the beggining of the secular Anthropic principle which generaly says that "We can ask questions about the Universe because it is as we know it, if it wasn't we couldn't be here to ask questions about it, it seems to have design because of this". In a way it is implying the existence of other Universes with no observers to ask the questions we do. To put it in another way:

"The principle was formulated as a response to a series of observations that the laws of nature and parameters of the Universe take on values that are consistent with conditions for life as we know it rather than a set of values that would not be consistent with life as observed on Earth. The anthropic principle states that this phenomenon is a necessity because living observers wouldn't be able to exist, and hence, observe the Universe, were these laws and constants not constituted in this way." - Wikipedia

There is also the possibility that these conditions are the only ones possible for a Universe.

However we have only one fact about all this. The fact is this Universe as we know it; the rest is speculation. Given this fact, I choose to say that the probability of an intelligent creating force is more likely than not.

I can understand why you would choose to be neutral... what I can't understand is why you say that in this context a God's existence is less likely.