This selection from Okasha includes two issues, whether there are limits to explanation (pp. 52-55) and whether all science reduces in the end to physics (pp. 55-57). The article by Fodor is concerned with the latter issue. The connection of this issue to explanation lies in the sort of explanation, explanation by “theoretical identification,” that Okasha discussed at the end of last time’s assignment (p. 52) and that appeared in van Fraassen via the Aristotelian idea of explanation by essence. For it is theoretical identifications that are used to “reduce” one science to another.
• After introducing the general issue of limits of explanation, Okasha focuses on idea of explaining a phenomenon of consciousness. He presents enough material for you to think about the issue, so let me just add one point of view he does not mention. Some have held (the philosopher Ludwig Wittgenstein, 1889-1951, is one example) that any sense that consciousness is a phenomenon or aspect of a phenomenon beyond the reach of science is the result of a misunderstanding of the way we speak about the mind. According to this view, the “subjective aspect” that Okasha mentions is not a phenomenon explainable by science simply because it is not a phenomenon at all.
• Jerrold Fodor is a philosopher of psychology, and issues related to the scientific explanation of mental phenomena are at the heart of his article, but his concern is not with any limits that might exist on the explanatory reach of psychology but rather on its autonomy from other sciences, from neurology in the first instance and ultimately from physics. His argument for this autonomy is based on the idea of “multiple realizability” mentioned by Okasha (p. 56f).
Fodor’s article is one of the longer supplementary assignments, and you may find it rather demanding. I cannot identify one part that is more important, but Fodor repeatedly stops to summarize his points, and I can tell you where to find these summaries. They will not be easy to follow without reading the rest of the article, but they may give you a sense of the relative importance of the other things he says.
• The last paragraph of the paper (p. 114) summarizes his whole argument and (apart from the idea of a “counterfactual,” which is sketched below) it does not require much special background.
• The last three pages of the paper (pp. 112-114) give a fuller argument for this conclusion and also summarize much of the discussion of section III.
• You can find earlier summaries of parts of the paper in the following places: the last paragraph of section I (p. 101), the two full paragraphs on the bottom half of p. 104 (which summarize the initial part of section II), the last two paragraphs of section II (p. 107), and, finally, the last paragraph of p. 109 (which provides a non-symbolic version and an example of the ideas in the diagram at the top of that page).
Fodor explains what he means by most of the technical ideas he uses, but his explanations sometimes come after he first uses the terms because he is assuming his readers already have rough idea of what they mean. Since you may not have already encountered these terms, you will need to be patient and try to understand them from context until he offers his explanation. I’ll add brief explanations of couple of ideas that he simply assumes (because there is nothing special about the way he uses them).
• A counterfactual is a conditional statement that concerns conditions that are plainly contrary-to-fact (e.g., “If Wabash were in the tropics it wouldn’t need snow removal equipment”). Many have suggested that lawlike generalizations are distinguished from others at least in part by the fact that they imply such conditionals. To use an example of Hempel’s, the generalization “All rocks in this box contain iron” is not a law even if true because it does not allow us to conclude “If this pebble had been put into the box, it would contain iron.”
• A disjunction is a sentence that gives two or more alternatives. Disjunctions are typically stated using the word “or,” and the v-like symbol Fodor uses is shorthand for this. The idea usually shows up in Fodor in connection with talk of “natural kinds.” He explains what he means by the latter idea on p. 102, and the last sentence p. 109 provides an example of his point about disjunction and natural kinds. Here’s another example. In general, natural kinds are supposed to have the same role in various sciences that species and higher classifications have in biology, and “or” can be used to form biological classifications that do not have this role. Think of the predicate “is a dog or a clam.” This will apply to a definite class of objects (i.e., all dogs and clams) but one that is unlikely to figure into any significant biological law.