One of my absolute favourites6 November, 2015 at 19:42 | Posted in Theory of Science & Methodology | 5 Comments
Inference to the Best Explanation can be seen as an extension of the idea of `self-evidencing’ explanations, where the phenomenon that is explained in turn provides an essential part of the reason for believing the explanation is correct. For example, a star’s speed of recession explains why its characteristic spectrum is red-shifted by a specified amount, but the observed red-shift may be an essential part of the reason the astronomer has for believing that the star is receding at that speed. Self-evidencing explanations exhibit a curious circularity, but this circularity is benign.
The recession is used to explain the red-shift and the red-shift is used to confirm the recession, yet the recession hypothesis may be both explanatory and well-supported. According to Inference to the Best Explanation, this is a common situation in science: hypotheses are supported by the very observations they are supposed to explain. Moreover, on this model, the observations support the hypothesis precisely because it would explain them. Inference to the Best Explanation thus partially inverts an otherwise natural view of the relationship between inference and explanation. According to that natural view, inference is prior to explanation. First the scientist must decide which hypotheses to accept; then, when called upon to explain some observation, she will draw from her pool of accepted hypotheses. According to Inference to the Best Explanation, by contrast, it is only by asking how well various hypotheses would explain the available evidence that she can determine which hypotheses merit acceptance. In this sense, Inference to the Best Explanation has it that explanation is prior to inference.