|"Here is obviously a powerful system for circular reasoning. Fossils are used as the only[sic] key for placing rocks in chronological order. The criterion for assigning fossils to specific places in that chronology is the assumed[sic] evolutionary progression[sic] of life; the assumed;sic] evolutionary progression[sic] is based on the fossil record so constructed. The main evidence for evolution is the assumption[sic] of evolution." --- Reverend H. Morris, Scientific Creationism|
The charge is based on a misrepresentation of the way in which
the geological time scale was actually constructed. The
geological time scale was set up before Darwin. It was
constructed by scientists who believed in events of special
creation (although they would not meet the requirements of
contemporary Creatioist orthodoxy, since they believed in
successive waves of creation). Early nineteenth-century
geologists used the sequence of fossil forms found throughout
the world to correlate strata. What they assumed was that
organisms found in lower strata had flourished before those
whose remains are buried in higher strata. This assumption bore
no commitment to the idea that the later organisms evolved from
the earlier ones.
Moreover, Morris ought to know that his account misrepresents geological practice in a different way. For he and his fellow Creationists argue vehemently against the use of a wide variety of independent methods for dating rocks that appeal to phenomena of radioactive decay. [....] Evidently, they believe that these methods are faulty. However, what is presently at issue is whether there is any independant method for assigning dates to rock strata. Morris asserts that fossils are "the only key" for ordering rocks in time. That is simply false, and he knows it. Rocks can be dated by using a family of radiomctric methods, as well as the techniques of classical stratigraphy. To claim that these methods do not succeed is to offer a different [false] criticism. One cannot simply ignore independent methods and then claim that they do not exist.
In fact, Morris cites a passage that tells directly against the point he wishes to make. He quotes a sensible sentence by three geologists (Stieff, Stem, and Eichler, cited in Morris 1974a, 144-145 Scientific Creationism) to the effect that the best assessment of ages should take into account the results of all the available techniques--- including paleontological evidence. Their judgment should remind us of two important points. First, there are many independent ways of assigning ages to rocks (or of telling which rocks preceded which others). Second, when geologists are interested in finding the age of a rock stratum as precisely as possible, they will standardly take into account the deliverances of all applicable methods.--- Philip Kitcher, Abusing Science. The Case Against Creationism