withallyourmind.net

I have been greatly blessed over the past few years to have had the (perhaps, rare) opportunity to reason through and argue important issues with my son, Jeremy. As he mentions periodically in his posts, he and I do not always reach the same conclusions in all matters, but there is certainly much more we agree on than disagree (especially in areas of essentials of Christian doctrine). He is an extremely gifted and intelligent young man (no fatherly bias here!) has certainly been correct on many occasions in which we disagreed and has helped me to correct my views. I hope there has been a reciprocal effect which my arguments have had on his views. Jeremy has been less enthralled with the intelligent design enterprise than I, although he sees many positives in the movement. Recently, he posted a blog in which he pointed out what he perceived as three flaws in Dembski’s explanatory filter:

1. It doesn’t allow us to detect real design that arose due to natural laws
2. It’s account of design detection is partly circular.
3. It doesn’t accurately capture how we actually make at least the majority of our justified design beliefs.

I disagree that the filter is flawed in the way Jeremy describes. He offers the Pluto analogy as an example of flaw #1. That if someday we were to arrive on Pluto and find a series of craters caused by various meteors that, when seen from afar spell out “Welcome to Pluto,” then even if we can trace the paths of each one of the meteors and their causes and find out they are explainable by law all the way back to the big bang, we would still be justified in inferring some sort of design. The first step in the filter asks if a certain finding is of necessity the way it is or is it contingent (could have been otherwise). If I understand Jeremy’s objection, the fact that those meteors could be shown to have necessarily had to land in those places due to prior conditions of the big bang, the filter would cause us to reject design as an explanation. So we would miss design where it in fact seems reasonable to assume design.

In response to this, first of all, I don’t think this is a flaw of the filter, but a strength. The filter is highly specific (very few false positives - it does not infer design if there is none) but has lower sensitivity (higher number of false negatives - it may say something is not designed when it in fact is). These built-in levels of specificity and sensivity insure that we do not make mistakes and ascribe something to design when it could have been produced without design. Additionally, although I think a less significant response to Jeremy’s objection, is that I’m not sure I would be convinced that anyone could show that those meteors actually had to land where they did on Pluto. This particular example would not necessarily be thrown into the rejected pile of non-designed events. Perhaps, I am wrong in this, but it does not seem obvious to me that this is so. Finally, let me quote Dembski (The Design Revolution, p 99) in reference to Jeremy’s proposed false dilemma:

Let me stress again, we are not dealing here with an either-or, pitting material mechanisms against design. Rather it is a question of one-or-both, pitting material mechanisms in isolation against material mechanisms working in tandem with design.

In response to flaw #2, that the problem of specification is circular and undercuts the whole purpose of the explanatory filter, I again disagree. I must admit that the concept of specification as offered by Dembski was a difficult one to wrap my mind around and understand. But I think, properly understood, it is not circular at all. I’ll have to address this in another post as I am out of time. (By the way, I still have two posts left in my series on Evangelicals and Roman Catholics and will finish that series soon.) (Also, by the way, this kind of back and forth between Jeremy and I is what I was referring to earlier that has been invaluable to me in my understanding on important issues. We, up until now, have not “taken it to the web.”)