Tuesday, May 21, 2013

Correction to Believing Bullshit, chpt 2.

Here's an endnote I am adding to a chapter I am contributing to the upcoming Handbook on Humanism (edited by AC Grayling and Andrew Copson [Wiley Blackwell publisher]). I now realize I got something wrong in chapter 2 of my book Believing Bullshit, so might as well set the record straight publicly. Here's the endnote of the chapter I am now writing for the new book [n.b. YEC = Young Earth Creationism]:

Elsewhere I have said that because Ken Ham’s theory makes no predictions – takes no risks – regarding the fossil record, so it cannot be confirmed by the fossil record. See “But It Fits!” in my Believing Bullshit (Amherst NY: Prometheus Press, 2011). I now realize I did not get this quite right. Were we to start excavating fossils that were clearly stamped “Made by God in 4,004 BC”, etc., that might indeed confirm – even strongly confirm – YEC, despite the fact that YEC does not predict such a discovery. True, such a discovery may not be probable given YEC, but, given the discovery is nevertheless considerably more probable on YEC than otherwise, it would still confirm YEC to a significant degree. 

So here's what I should have said in Believing Bullshit (from the new chapter):


There’s a popular myth about science that if you can make your theory consistent with the evidence, then you have shown that it is confirmed by that evidence - as confirmed as any other theory.

Proponents of ludicrous belief systems often exploit this myth. It is exploited by Ken Ham. It may also exploited by those who reinterpret their preferred scripture or prophecy in order to make it “fit”.

Of course, achieving “fit” and achieving confirmation are not the same thing.

As we saw earlier, a theory can be strongly confirmed by making a risky prediction - by predicting something that would not be particularly likely if the theory were false.

The theory of evolution and common descent, in its fully developed form, does indeed make many such risky predictions – predictions that turn out to be true. That means it is strongly confirmed.

Take the fossil record, for example. The theory predicts fossils will be dug up in a very specific order. It predicts, among other things, that, because mammals and birds are a comparatively late evolutionary development, their fossils will never be discovered within the earlier, pre-Devonian sedimentary layers (which contain over half the fossil history of multicellular organisms). If the theory of evolution were false and YEC true, on the other hand, there would be no particular reason to expect a complete absence of mammal and bird fossils in those earlier deposits (indeed, YECs wouldn’t be at all surprised had such fossils shown up). Yet, among the countless thousands of fossils excavated each year, not a single example of a pre-Devonian mammal or bird has ever been found. That’s some coincidence if the theory of evolution is false. (Note this is just one example of how the theory of evolution is strongly confirmed. There are numerous others.[i])

By contrast, Ken Ham’s brand of YEC studiously avoids making such risky predictions regarding the fossil record. Whatever order the fossils are dug up is of no consequence to YEC. Mammals and birds in the pre-Devonian - fine. No mammals and birds in the pre-Devonian – no problem. For this reason, while the ordering of those fossils that have been excavated does strongly confirm the theory of evolution, it does not strongly confirm YEC.[ii][iii]



[i] See for example the talk Origins archive entry by Douglas Theobald, 29+ Evidences for Macro-evolution Part 1: the Unique Universal Phylogenetic Tree. Available online at http://www.talkorigins.org/faqs/comdesc/section1.html

[ii] Elsewhere I have said that because Ham’s theory makes no predictions – takes no risks – regarding the fossil record, so it cannot be confirmed by the fossil record. See “But It Fits!” in my Believing Bullshit (Amherst NY: Prometheus Press, 2011). I now realize I did not get this quite right. Were we to start excavating fossils that were clearly stamped “Made by God in 4,004 BC”, etc., that might indeed confirm – even strongly confirm – YEC, despite the fact that YEC does not predict such a discovery. True, such a discovery may not be probable given YEC, but, given the discovery is nevertheless considerably more probable on YEC than otherwise, it would still confirm YEC to a significant degree.

[iii] Also notice that each new assumption Ham introduces to try to explain away the evidence against YEC has the effect of reducing the prior probability of his overall theory. Ham succeeds in endlessly protecting YEC against empirical refutation only by endlessly reducing the prior probability that YEC is true.

5 comments:

wakawakwaka said...

hey Dr.law, is the reason why Ken Ham uses "presuppositional" arguments, like Sye Ten, because he just wants to enforce what he wants to believe to make himself feel better and not sad after realizing that his dogma is challenged by actual science?

Reynold said...

I've always believed that the rise of the presuppers is itself evidence that the apologists themselves are starting to realize that, deep down, they really do not have actual evidence on their side.

I remember reading in Ronald Number's book "The Creationists" that the reason that Henry Morris insisted on that "statement of faith" that originally his group then the others, were required to take was because they kept losing members when they went to normal colleges/universities.

On a related note, I know of at least one guy who is not impressed at all by the 29+ Evidences for Macroevolution site. He believes that all those scientists have somehow picked "tests" that are all "safe".

Ironically...he's no xian nor a creationist. He doesn't care for either Dan nor Sye himself!

TaiChi said...

If Ken Ham's theory would be confirmed by finding date-stamped fossils, then it is also true that Ham's theory is disconfirmed, to some degree, by the fact that we have not found any such fossils*. I suspect, however, that Ham may not accept that his theory is slightly disconfirmed by the lack of date-stamped fossils. On the contrary, he might say, the lack of date-stamped fossils is to be expected given that God wants his people to have faith in his existence, that the possibility of doubt is required for faith, and that such fossils would remove that possibility of doubt by being too obvious. This is a new theory, which would actually be disconfirmed by date-stamped fossils, and confirmed by our not finding such fossils.

* Analogous example: a lack of transitional fossils would be disconfirmatory for the theory of evolution.

"Elsewhere I have said that because Ken Ham’s theory makes no predictions – takes no risks – regarding the fossil record, so it cannot be confirmed by the fossil record."

Either way, I agree that we should not describe Ham's theory as predicting such fossils, given that they are less than probable on his theory. In that case, the focus on predictions can be misleading: that a theory makes no predictions gives us no guidance as to whether a theory is (dis)confirmed, nor whether any evidence could (dis)confirm it. Perhaps then you should talk about a theory's generating no 'confirming or disconfirming instances', or its having 'no empirical content', rather than its lack of predictions?

Peter Monnerjahn said...

“Risky prediction” seems to echo an idea that Karl Popper systematised and popularised. (A good introduction is this excerpt from a chapter of his Conjectures and Refutations.) Is that intended? If so, I’d be delighted to start a conversation about the wider context and implications of Popper’s philosophy (on which I am doing a PhD).

wakawakwaka said...

but the thing is though, presupptionalism doesnt seem to make alot of sense outside of Calvinistic thinking, and its mostly calvinists who use it anyways