While the Trigonia story is a microcosmic representation of nineteenth-century evolutionary debates, it also serves as a model for assessing the impact of new empirical material upon a controversial issue potentially explained by several internally consistent but contradictory theories; for there can be no fact quite so pristine as a discovery anticipated by no one. The reaction to modern trigonians was, I suspect, completely typical; all parties to the dispute managed to incorporate the new datum into their systems. Evolutionists emphasized the morphological differences between Mesozoic and modern forms and assumed that the disjunct distribution was an artifact of an imperfect record. Agassiz cited the known distribution in support of special creation, but announced that the discovery of a Tertiary species would discredit none of his ideas. Parkinson could not readily encompass the difference without evident improvement in his progressionist synthesis, but invoked almighty wisdom in his ignorance.
I do not doublt that all these naturalists proceeded properly in refusing to yield to the anomalies of a single fact which destroyed no deductive sequence in any of their theories. When one considers the stupendous amount of misinformation current in early nineteenth-century scientific circles,49 it is easy to appreciate the salutary aspects of stubbornness in the face of inevitable contradictory citations.
De Beer50 has marveled at Darwin's ability, in the 1844 sketch, to work his way through a mire of misinformation: “It is a matter for wonder that with the meagre materials at his disposal he was able to steer a straight course across a largely uncharted ocean of ignorance, with rocks of falsehood right across his path.” Yet Darwin approached these rocks with the idea of natural selection already firmly in mind. Any pure empiricist would have surrendered to confusion long before 1859.
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