In a recent post at the Uncommon Descent blog, Eric Holloway has given a clear explanation of why ID is not science. That may not be what Eric was intending to explain, but he succeeded whether or not it was his intention.
Eric uses the Aristotlean notions of “efficient cause” and “final cause”, with efficient causes being used in answers to the “how” question and final causes being used in answers to the “why” question. And Eric is clear on putting ID explanations in the final cause category.
Now, to relate these concepts back to the interplay between materialism and ID, materialism implies that all events only have efficient causal explanations, and any perceived final causal explanations can be reduced to efficient causal explanations.
I’m not sure what is this “materialism” that Eric speaks of. If materialism says that, then its a good reason to not be a materialist. Science seeks causal explanations. But most scientists do not deny that there can also be final cause explanations. It is just that the final cause explanation is not science.
Let’s suppose that I want to build a house. I hire architects to design it, and a construction firm to build it. The way that all of the parts are put together to assemble the house constitutes the efficient cause explanation. My intention and the insight of the architect are part of the final cause explanation. Now if somebody else wants to build a house, then the efficient cause explanation can be very useful. The final cause explanation might make interesting history, but it isn’t of much use to those who want to build houses, because it only answers the “why” question and fails to address the “how” question.
The main issue of ID has always been on whether ID is science. Critics of ID fully understand that people ask the “why” question, and wonder about questions of origins. But it is the “how” question that matters to science. The primary objection to ID has always been an objection to attempts to force the teaching of ID into the science classroom.
A recent cartoon illustrates that the “why” question is not one of concern for science.