Monday, November 15, 2010

Various Positions on Analogical Inferences

A while back, in talking about the fallacy of false analogy, I noted that the fallacy, as typically understood, seems traceable to Mill, and that Mill makes it a fallacy because he has a particular view of analogical inference that is controvertible. In discussing Mill's account of analogical inference I called him a minimalist, and contrasted him with Hume, who I called a maximalist. When Alan asked some questions about this, I gave an answer, but I think both my original classification and my response were made unnecessarily murky by a failure to distinguish two key questions a good account of analogical inference would have to answer:

(1) Can good analogical inferences oppose each other?

(2) Must analogies meet some condition beyond real resemblance in order to be good?

Let's call a position that requires a Yes to the first question, inclusivism (it includes opposing inferences as legitimate), and the negative complement, exclusivism. And let's call a position that requires a Yes to the second question, restrictivism (it restricts the conditions under which analogies can be good in the first place), and the negative complement, generalism. We can then better see the position between Mill on the one hand and Hume and myself on the other. Mill is an exclusivist restrictivist. He thinks that any analogical inference that gets an incorrect conclusion is fallacious; and he thinks that good analogical inferences, in addition to the resemblance of the analogy itself, also need to build on an established causal connection. Hume, on the other hand, is an inclusivist generalist (as am I). He thinks that even good analogical inferences are defeasible, and he thinks that all an analogical inference needs in order to be a good inference (albeit one that can be defeated by better or stronger inferences) is resemblance. Indeed, he explicitly says that no matter how imperfect the resemblance may be, the inference "may still retain as much as may be the foundation of probability, as long as there is any resemblance remaining".

Putting it this way raises the question of whether the history of philosophy also includes inclusivist restrictivists and exclusivist generalists. An inclusivist restrictivist would have to hold that (1) good analogical inferences can oppose each other and also hold that (2) something more is needed for a good analogical inference than just some sort of resemblance or analogy. This is obviously a coherent position. I can't think of any significant name in the history of philosophy that holds it, but there really aren't that many significant names in the history of philosophy who discuss analogical inference at length. An exclusivist generalist would have to hold that (1) good analogical inferences cannot oppose each other and yet that (2) all that is required for a good analogical inference is resemblance. This seems like it would be an extraordinarily difficult and unintuitive position to hold, and perhaps an impossible one. At the least one would have to say that a lot of things that seem to resemble each other don't actually resemble each other at all (not 'at all' in the sense of 'in all the most important ways', but 'at all' in the sense of at all). This would take some doing, and I doubt anyone has ever taken the exclusivist generalist line on analogical inferences.