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.