Monday, February 27, 2012

Week 3: Explanation and Induction

In addition to questions about realism, Lipton aims to settle issues about inductive inference (Chapter 1). In short, his claim is that despite the apparent diversity of inductive inferences, many of them can be captured as special cases of a pattern of reasoning called Inference to the Best Explanation (IBE). Lycan (2002) lays out a more general program, explanationism, of which Lipton’s can be seen as a special case. We’ll also read Laurence Bonjour’s short review of the major problems of induction.
            Neither Lipton nor Lycan take themselves to be tackling the classic, Humean problem of induction—what Lipton calls the “problem of justification.” The problem of justification asks, “How are we ever entitled to believe things on the basis of inductive inference?” Instead, they take themselves to be addressing the “problem of description,” in which the problem is to devise an elegant classification of the kinds of inductive inferences we take as warranted.
            Solutions to the two problems can be separated. The problem of description—at least as construed by Lipton and Lycan--only assumes that some inductive inferences appear justified, and aims to explain this appearance in terms of explanatory roles played by the conclusions of these inferences. It could turn out that this is merely an appearance of justification, in which case the problem of description would be entirely distinct from the problem of justification.
            Conversely, solutions to the problem of justification can proceed without a very detailed classification/description of our inductive practices. All inductive inferences share certain features—e.g. that the premises of an inductive inference can be true whilst its conclusion be false. Furthermore, it’s precisely these common features that drive the problem of justification. Consequently, if we can justify the assumptions concerning these features, then we don’t need any further description of the kinds of inductive inferences that we employ.
            Of course, there’s nothing that prohibits concerns about description and justification from informing one another. In particular, if we think that the “meta-philosophy” that underwrites Humean skepticism unreasonably privileges philosophical reflection over other kinds methods, then explanationism might be justified in part by its ability to provide a good classification/description of our inductive practices. (Compare: our theory of atomic structure is justified in part by the periodic table’s ability to provide a good classification of the elements.) Indeed, Lipton gestures towards this maneuver later in his book.
So why should we care about the relationship between explanation and truth? In addition to the issues about realism raised last week, considerations about explanation also promise to offer a powerful description of our inductive practices. Since induction figures prominently in nearly all of our inquiries, this means that explanation would figure prominently in most of our inquiries. Consequently, if the connection between explanation and truth is tenuous, then we have to adjudicate between several scenarios: (1) that our inquiries properly aim for explanation/understanding but only incidentally aim for truth, (2) that our inquiries properly aim for truth but only incidentally aim for explanation/understanding, or (3) that our inquiries only incidentally aim for truth and only incidentally aim for explanation/understanding. So our self-conception as inquirers is at stake! That’s why we should care.


  1. Thank you to James for a great summary and discussion. I'd like to take a stab at your third discussion question, specifically concerning how Lycan's proposal of "reflective equilibrium" might relate to deductive reasoning. Lycan does indeed seem to suggest (I guess following Goodman [1955]) that those iron-clad Aristotelian rules of logic which many hold as first principles, or axiomatic, or self-evident, are in fact the result of a process of reflective equilibrium, making them (merely) normative and not logically necessary (any more than the rules or virtues of inductive inference).

    Question: Is that really what he's saying? He points out correctly that we can give no justification proper of Modus Ponens (for example) – but is the way in which Modus Ponens is unjustifiable comparable to the way IBE is? For the former admits of no doubt. Do we think it likely that our logic evolved by reflective equilibrium, rather than being really a priori?

    Or perhaps I’m misunderstanding him.

  2. The Bayes' theorem starts out with the assumption that we have some knowledge of prior probability, but the theorem itself does not offer any resources to admit certain prior beliefs while reject others. Given its widely acknowledged mathematical eloquence, could you tell me more on some of the reasons to endorse this hidden assumption in Bayesian epistemology? Say there are two questions that need to be answered. The first one asks how we choose between a given set of beliefs in the first place. The other one asks how we can "rationally" get to a posterior belief given the information we have on a prior belief. The Bayes' theorem seems to shed some light on the second question without answering the first question. But shouldn't the second question be a subquestion of the first one? I hope this explains why i am espeically interested in knowing more about the criteria for prior probability/belief justification.

  3. I wanted to elaborate on your second question: I initially read Lycan’s article “Judgment and Justification” instead of Lycan’s later article, “Explanation and epistemology.” After reading Professor Khalifa’s prompt, however, I wanted to briefly outline an argument that Lycan makes in the first article, show how it is applicable and fits with the actual readings, and then raise the intractable question of truth.

    Lycan, in today’s reading, advances a natural/evolutionary biology explanation for adequacy the explanatory virtues. While substantial and mostly complete, Lycan gives a more thorough explication and defense in “Judgment and Justification.” For our discussion, we should note that Lycan introduces and defends the idea of the teleology of our justification virtues — just as the liver filtrates blood, according to evolutionary biology, simplicity, power, etc. all further existence in a complex yet seemingly predictable world, according to evolutionary cognitive science. Importantly, this is not a vitalism but rather a pragmatic and empirical practice that shows that what nature provides is not perfect, but merely “pretty damn good” (153).

    These virtues are value neutral methods that admit no why, but rather, possibly, how and how could we transcend or further their development. Why is not the correct question. Or as, Lycann claims, we are not attempting to access “capital T truth” but rather aiming to survive and progress. So, the question is - especially in relation to Professor K's last paragraph - what are we actually aiming at and with what?

  4. I want to push Professor Khalifa a bit with his suggestion that we should care about he problem of induction. First of all, I would hope that no one is losing sleep over this problem.

    Given last week's readings, I became fairly convinced of the untenable nature of realism. For an anti-realist, how is the problem of induction a problem at all? If I merely think that truth, or perhaps simply the aim of science, is empirical adequacy, why do I care whether my inductive inferences are more than empirically adequate? Why can I not say, "My inferences are true/empirically adequate up until the point when an empirical event disproves them?"

    The problem of induction is something I had acknowledged to be a real problem in the past, but I'm not sure how big a deal it is if you are an anti-realist.

  5. I also wanted to probe the reason why we should care about the relationship between explanation and truth. In society, we mostly see truth in some sense as a method of governance - we use truths to determine our actions and control our lives. That alone should suffice for a good reason why we should care. Experts have the greatest credibilities for discussing truth and most people will believe their words without question.