Inferring and Explaining

ChaPter fIVe Inference to the Best Explanation In making this inference one infers, from the fact that a certain hypothesis would explain the evidence, to the truth of that hypothesis. In general, there will be several hypotheses whichmight explain the evidence, so one must be able to reject all such alternative hypotheses before one is warranted in making the inference. Tus, one infers, from the premise that a given hypothesis would provide a “bet- ter” explanation for the evidence than would any other hypothesis, to the conclu- sion that the given hypothesis is true. —GIlBert harman 1 Inference to the Best Explanation We have been treating the expression inference to the best explanation as technical jargon. It is a way of looking at evidence or at least purported evidence in an inductive argument. If we look at the component words in this expression, we will discover quite a lot. First of all, we are deal- ing with an inference . For most purposes, we can consider this as just another way of saying that we have an argument to be considered. Tis inference is to an explanation . But we are not dealing with just an inference to an explanation but to the best explanation. Tis implies two very important things. First, in order for there to be a comparison, there must be other possible explanations of the data in the argument, rival explanations . And the argument is also commit- ted to this original explanation being better than all these rivals.Terefore there seems to be some rank ordering of the explanatory candidates, even if this is not explicitly stated. I will use all this as a way of articulating a test of the quality of evidence within an argument. Tis test will be most straightforward when you are what I have called a consumer of an argu- ment. Connie thought she had evidence that her 37