Responding to a challenge from Paul
Paul (http://exilefromgroggs.blogspot.com/) has issued a challenge to ID opponents to come up with a way formalising the detection of design. I can resist this. But the response is rather long so I have put it here.
Paul
You are assuming that there is a universal way of detecting if something is designed. I would claim that you can only decide if something is designed given some context. For example, I am pretty sure Stonehenge was designed. Why? Because my experience tells me something about how stones generally get arranged in nature. (But you might be interested in http://w3g.gkss.de/staff/storch/pdf/misuses.pdf ) and also something about how people arrange stones intentionally. I can look at the result and compare the chances of the result happening given the two explanations. I can also investigate details of the process. If Stonehenge was designed it would have required extraordinary dedication and resources but it is feasible.
In another context it is far more difficult to make the call. Suppose I we discover a configuration of stalactites that happen to form a similar pattern to Stonehenge (roughly circular). Did someone make that happen by design or was it a freak of nature? We can’t decide this simply by studying the result. We have to look at the details of how the pattern might have been generated naturally or by design. Was there anyone around at the time the stalactites formed? How could they have implemented the pattern? Alternatively what natural process might have lead to the pattern? An interesting possibility might be that we discover that stalactites often form patterns like this even though we are not sure why. Do we now deduce there is a stalactite designer masterminding these patterns or do we simply say – let’s investigate how this might have happened?
There is another important aspect to this deduction. To estimate the probability of explanation X for outcome Y I need to do two fundamental things. One is estimate the probability of Y given X – e.g. what are the chances of getting this result if was designed? The other is to estimate the a priori probability of X. Then I can invoke Bayes’ theorem P(XY) = P(X)*P(YX). In the case of Stonehenge I know independently of Stonehenge that there were people around at the time capable and very likely motivated to build something of this type. So the probability of there being a designer P(X) is high. So both P(X) and P(XY) are high and I can reasonable deduce P(XY) is high. In the case of the Stalactite pattern I have no knowledge of any such designer so P(X) is low. The extreme case is when anyone claims that the world is the way it is because an omnipotent God made it that way. Now P(YX) = 1 – if there is such a God and it is truly omnipotent and it wants to make things this way then it is certain it would succeed. But P(XY) is not high because we have no a priori evidence that there is such a God who wanted things to be this way. P(X) is very low.
That’s a lot of writing – I hope it helps.
Cheers
Paul
You are assuming that there is a universal way of detecting if something is designed. I would claim that you can only decide if something is designed given some context. For example, I am pretty sure Stonehenge was designed. Why? Because my experience tells me something about how stones generally get arranged in nature. (But you might be interested in http://w3g.gkss.de/staff/storch/pdf/misuses.pdf ) and also something about how people arrange stones intentionally. I can look at the result and compare the chances of the result happening given the two explanations. I can also investigate details of the process. If Stonehenge was designed it would have required extraordinary dedication and resources but it is feasible.
In another context it is far more difficult to make the call. Suppose I we discover a configuration of stalactites that happen to form a similar pattern to Stonehenge (roughly circular). Did someone make that happen by design or was it a freak of nature? We can’t decide this simply by studying the result. We have to look at the details of how the pattern might have been generated naturally or by design. Was there anyone around at the time the stalactites formed? How could they have implemented the pattern? Alternatively what natural process might have lead to the pattern? An interesting possibility might be that we discover that stalactites often form patterns like this even though we are not sure why. Do we now deduce there is a stalactite designer masterminding these patterns or do we simply say – let’s investigate how this might have happened?
There is another important aspect to this deduction. To estimate the probability of explanation X for outcome Y I need to do two fundamental things. One is estimate the probability of Y given X – e.g. what are the chances of getting this result if was designed? The other is to estimate the a priori probability of X. Then I can invoke Bayes’ theorem P(XY) = P(X)*P(YX). In the case of Stonehenge I know independently of Stonehenge that there were people around at the time capable and very likely motivated to build something of this type. So the probability of there being a designer P(X) is high. So both P(X) and P(XY) are high and I can reasonable deduce P(XY) is high. In the case of the Stalactite pattern I have no knowledge of any such designer so P(X) is low. The extreme case is when anyone claims that the world is the way it is because an omnipotent God made it that way. Now P(YX) = 1 – if there is such a God and it is truly omnipotent and it wants to make things this way then it is certain it would succeed. But P(XY) is not high because we have no a priori evidence that there is such a God who wanted things to be this way. P(X) is very low.
That’s a lot of writing – I hope it helps.
Cheers
posted by Mark Frank at 12:07 pm
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