Is ID Science?
Meyer discusses the nature of “historical sciences” such as geology and paleontology and evolutionary biology and argues that they use different methods to “experimental sciences” such as physics and chemistry. He states that Stephen Jay Gould accepted this distinction and argued that historical scientific theories were testable by analysing their “explanatory power” (Gould, “Evolution and the Triumph of Homology”) Gould describes the process of testing in historical sciences as seeking “consilience”. Consilience is the situation where many facts can be explained well by a single proposition or theory. Gould he says argues that historical sciences depend upon the knowledge of the laws of nature to make inferences about the past.
Meyer then asks whether a design hypothesis can be formulated as a historical scientific theory about what happened in the past.
Historical scientists cite the occurrence of an event or series of events in the past as the explanation for some observable phenomenon in the present. Historical scientists use a distinctive mode of reasoning. Using their knowledge of cause and effect relationships historical scientists “calculate backwards” and infer past conditions and causes from present conditions and causes.
This type of reasoning is called “abductive” reasoning as opposed to inductive(in which a universal law is established from repeated observations) or deductive (in which a particular fact is deduced by applying a general law to another particular case. Abductive logic was first described by Charles Sanders Pierce
Despite the tentative nature of abductive reasoning we do make conclusive inferences about the past.
A conclusion of abductive reasoning is certain if we cannot explain the currently observed facts without the past cause. An abductive conclusion is established by showing that it is either the best or the only explanation of the effects in question.
To address this problem in geology Thomas Chamberlain proposed a method of “multiple working hypotheses. This is also known as “inference to the best explanation”
Peter Lipton is associated with this way of reasoning arguing that it is used both in science and ordinary life. Discovering certain particular marks in fresh snow we infer that a person with snow shoes has passed this way. Lipton argued that the ability to explain particular facts sometimes mattered more than predictive success in the evaluation of a particular hypothesis.
The problem with this method of assessing explanations is exactly how we judge which is the best explanation as opposed to the explanation we like the best.