Darwin’s Boulders and the human face of induction
|December 23, 2009||Posted by David Tyler under Intelligent Design|
As a young man aboard HMS Beagle, Charles Darwin was fascinated by erratic boulders. After completing his voyage, he wrote several papers about their origin. Tierra del Fuego was of particular interest, for he found boulder trains at different elevations at a place known as Bahia San Sebastian, which faces the Atlantic Ocean. Darwin actually delayed the survey work of HMS Beagle so he could gather more extensive information. On returning to the UK, he made the boulders the focus of two geological papers published in 1841. The route by which Darwin reached his conclusions is instructive for all of us involved in research today.
[Details omitted of how Darwin interpreted the boulders and of the recently published revised interpretation ]
Inductive reasoning starts with observations and philosophical premises, uses reason to identify patterns, which lead to the proposal of initial hypotheses. These can then be tested and confirmed hypotheses lead to theories. Darwin’s observations were of angular erratic boulders, the ability of icebergs to carry large rocks over long distances, and relatively short glaciers in the upland areas. His philosophical premise was uniformitarianism. Put these together and the hypotheses were iceberg rafting or stream-ice rafting. The angularity of the boulders ruled out stream-ice rafting, so Darwin drew the conclusion that the mechanism was iceberg rafting.
The problems with this start with the philosophical premises. Once uniformitarianism was accepted as essential to science (as Lyell argued), Darwin felt honour-bound to adhere to it. His thinking became constrained. He was only prepared to work with hypotheses that were compatible with uniformitarianism – all else would be regarded as speculation or even antiscience. This led him to overlook data that was right in front of him: the “tight distribution” of the boulders that was inconsistent with the hypothesis. It also delayed the recognition of the glacial features that covered Tierra del Fuego.
The problem goes back to Francis Bacon, who wanted to move away from the deductive methodology of the Aristotelians and establish something more grounded in empiricism. Induction was a key stage in his methodology – but he underplayed the human dimension. Researchers have to bring philosophical premises to bear on their work. How can we avoid becoming slaves to our adopted premises? Uniformitarianism lasted a century before researchers accepted that catastrophism was just as viable as a philosophical presupposition. What matters is that we use these philosophical approaches to generate testable hypotheses. Multiple working hypotheses are to be commended as long as ways are found to put them to the test.
Charles Darwin never escaped uniformitarianism. It pervaded his geology – as is apparent from the example before us here. It entered his thinking about biological transformation: the natural selection of small incremental variations. (Unfortunately, this constraint is still with us today, as Darwinians are unwilling to concede anything significant to the theory of punctuated equilibrium or to evo-devo.) Darwin missed out in understanding heredity, because he was looking for gradual change rather than discontinuous variation. (For more on why Darwin did not discover the laws of inheritance, go here).
For more – on why ID thinking is essential for the scholarly world to be healthy – go here.