最佳說明推論如何證成？：以達爾文《物種源始》中的論證作為案例研究

How to Justify Inference to the Best Explanation?: An Inquiry Based on Darwin’s Argument in The Origin of Species

根據最佳說明推論規則，我們可以從最佳說明的假說，正當地推論出該假說很可能為真。這樣的推論規則，不只在日常生活中廣被使用，也在科學研究活動中屢見不鮮。我們經常根據某個假說是最佳的說明，去證成該假說很可能為真。然而，最佳說明推論的可靠性卻受到挑戰：杭格福的反對；伏爾泰的反對；以及濫竽充數論證。在本文中，我論證達爾文式的最佳說明推論可被證成，這包括了：（一）我贊成達爾文在《物種源始》中為天擇說辯護的論證，可以說成是最佳說明推論的應用。（二）但是達爾文式的最佳說明推論有個特色，即它對於何謂最佳說明設有額外的要求。（三）論證達爾文式的最佳說明推論可以回應上述三種對於最佳說明推論之可靠性的質疑，因此可被證成。

When one infers, among available explanations, that the best one is (the most likely to be) true, she is following the rule of inference to the best explanation. Such a rule, not surprisingly, is frequently followed by ordinary people in daily life, and by scientists as well in the course of research. However, objections arise as to the justifiability of the inference to the best explanation: Hungerford’s objection; Voltaire’s objection; and the argument from a bad lot. In this paper, I argue that Darwinian Inference to the Best Explanation (DIBE) can be justified: (1) I will endorse the view that, throughout Origin of Species, Darwin’s argument for the theory of natural selection, hopefully, can be characterized as an inference to the best explanation. (2) But what is special with DIBE, as I will point out, is that it adds extra requirements on what counts as the best explanation. (3) I will argue that DIBE can meet the objections against the reliability of Inference to the best explanation, and thus that it can be justified.