EXPLANATIONS
Another minor complication arises with explanations. For present purposes we may define an explanation as follows:
An explanation is an account intended to show how it came to be that a fact or event is the way it is.
Now, explanations involve the giving of reasons, just as arguments do, and these are introduced by premise indicators like “for” and “because.” But many philosophers hold that not all explanations are arguments. Consider the statement:
He caught AIDS because he got a transfusion of blood infected with the HIV virus.
This passage involves the inference indicator “because...,” and we can see that “he got a transfusion of blood infected with the HIV virus” is being given as the cause of his having AIDS. But are we being asked to make an inference? Is it being given as a reason to persuade us that he caught AIDS? Many would say that the statement is being given as a reason why he caught AIDS, but it does not seem to be “intended to establish the conclusion” that he caught AIDS—this seems to be a fact regarded as given. According to these philosophers, reasons are not always given in support of a conclusion; they are also given to explain a fact.
Others disagree, and hold that in explaining a fact you are always giving an argument. Even though the conclusion may be understood, there are many causal hypotheses or accounts you can give of why it has come to pass. In each of these accounts, the (agreed upon) conclusion will be inferred from some putative premises, which may or may not constitute a good argument for the state of affairs in the conclusion having come to pass for those reasons.
This is not an issue we need to resolve here, however. We are interested in explanations only insofar as they can be interpreted as arguments. And we can determine this solely by reference to the above definition of an argument. To see how this works, let’s look at another example.
Christopher Columbus wrote of some of the inhabitants of the “New World”:
They bear no arms, nor know thereof. For I showed them swords and they grasped them by the blade and cut themselves through ignorance.
That they bear no arms is not being argued for or explained. But what about the natives’ knowledge of arms? The premise indicator “For” introduces Columbus’ reasons for thinking that the natives did not even know of weapons, which invites us to make the same inference. Thus the statement is best interpreted as constituting an argument. It is at the same time the best explanation of the aboriginals’ behaviour. This kind of argument is called inference to the best explanation.
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