Guillermoe: Champion of Abductive Reasoning at the Heart of the Design Inference
|October 3, 2014||Posted by Barry Arrington under Intelligent Design|
Guillermoe has very quickly become one of our most ardent critics on these pages. That is why it was so interesting to watch him walk right into a trap that HeKS cunningly set for him. Here it is:
We know what designed Stonehenge: HUMANS!!
How do you know this?
PAST EXPERIENCE. We know humans build things because we have observed that they do.
How do you know it was humans rather than aliens?
Because our past experience proves that humans exist and does not prove that aliens exist, so it’s much much more likely that humans built Stonehenge. That allows us to say A LOT of things about the designers of Stonehenge. What can we say about the intelligent designer of life on Earth?
Guillermoe obviously did not see the trap. Not only did he walk right into it, but the trap was so craftily set that he did not realize he was in it once he was there. Let’s see how.
Step 1: Guillermo admits there cannot be the slightest doubt that the circle of upright stones in Wiltshire, England known as Stonehenge was designed. He insists that we can know it was designed only because we can “know” that humans designed it.
Step 2: HeKS sets the trap by asking how we “know” it was designed by humans instead of, say, aliens, and Guillermoe walks right into the trap and makes himself at home. Guillermoe appeals to universal experience to make an inference based on abductive reasoning. To see how this is so, let us take a moment to explore the nature of abductive reasoning.
Abductive reasoning takes the form of inferring a cause X as an explanation for an effect Y when X is the most plausible explanation for Y. So, for example, if my lawn is wet this morning I might infer that it rained last night as the best explanation for the lawn being wet.
Abductive reasoning is different from deductive reasoning. In deductive reasoning if the premises are true the conclusion follows necessarily as a matter of logic. But even if the premise of the abductive inference is true (rain the previous night makes my lawn wet in the morning), the conclusion might nevertheless be false. It is possible, for example, that someone drove a water tanker and sprayed my lawn with water. Thus, an abductive inference is not logically compelled like a deductive conclusion. That is why it is called “inference to the BEST explanation,” not “inference to the only explanation”. Note that when a particular cause X is the only known cause of a particular effect Y, the abductive inference is much stronger.
GUILLERMO MAKES AN ABDUCTIVE INFERENCE
HeKS asked Guillermoe how he knows that humans rather than aliens built Stonehenge, and Guillermoe made the following abductive argument:
1. Stonehenge is a monument.
2. With respect to all monuments whose provenance is actually known for certain, the sole known cause of the monuments has been “built by humans.”
3. Therefore, it is much more likely (inference to best explanation) that humans built Stonehenge.
Guillermoe’s argument took the form “X is the generally most plausible cause of effect Y. We see a specific instance of Y; therefore the best explanation of this instance of Y is X.” In other words, we infer that X is the best current explanation of this Y.
Guillermoe moved off of his original overstated conclusion. He went from we “know” who built Stonehenge (obviously we know no such thing) to its “much more likely that humans built Stonehenge” (a perfectly sound abductive inference).
Notice how without knowing it Guillermoe has given away the store from a materialist perspective. He has tacitly acknowledged that with respect to a particular instance of apparent design, we cannot make an infallible deductive conclusion concerning the provenance of the design. The best we can do is make an abductive inference to best explanation. In doing so Guillermoe has validated the mode of reasoning at the heart of the ID program.
In exactly the same way, the ID proponent observes some aspect of living things that even the most ardent atheist will admit appears to be designed for a purpose, the digital code in DNA for example. He then notes that X (intelligent agency) is a possible cause of this effect Y (digital code). He goes one step further and notes that “intelligent agency” is the only known cause of the effect “digital code” where the provenance of the digital code has been actually observed. Therefore, we infer that the best explanation for this particular instance of digital code is “intelligent agency.”
Guillermoe is well and truly stuck. With respect to the DNA code effect, for example, in order to wiggle out of the trap set by his own reasoning he has three options:
1. Deny that the DNA code is a digital code. This is absurd.
2. Deny that the only known cause of digital code where the provenance is actually known is intelligent agency. An obvious falsehood
3. Beg the question by saying we “know” chance/necessity can account for the DNA code. Of course, we “know” no such thing. It is routinely assumed; it has never been demonstrated.