[Sorry about the length; my brain didn't want to stop. I'll break it up into a couple comments if need be. ]
What if i interpret the above to show that philosophers should not do psychology? Certainly, figuring out the best way to reason has been as important in philosophy (if not more than) figuring out how we actually reason.
Sometimes philosophers screw it up and confuse a normative claim for a descriptive claim. Perhaps (and I am not committed to this as anything more than a possibility) classical Aristotelian categories are not the way we actually represent categories when we're being lazy or care-free, but when we are trying to reason with the highest certainty possible, Aristotelian categories work best.
Is there no natural human category which is truly binary, has sufficient and necessary causes, and is semantic? 'Electron', or 'quark' seem plausibly Aristotelian to my intuition, and are certainly semantic.
On the other hand, we may sometimes run into a target of inquiry which requires that we form concepts for its study, but there are no Aristotelian categories which do the job, due to the nature of the target. In this case, we should definitely use fuzzy logics and the like; but I wouldn't doubt that the closer your fuzzy sets approximate Aristotelian categories, the easier categorical inference becomes.
So, if you are simply claiming that brains do not always use Aristotelian categories, I agree, and think you have provided sufficient evidence for the claim. But this is not so much a hit to philosophers doing logic/philosophy coming from discoveries in cog-sci, as it a hit to philosophers doing cog-sci coming from cog-sci. However, if you would go on to say that we shouldn't treat categories as Aristotelian-lyish as possible in philosophy/logic, I would say that you have not done enough to show this (not to say that LW doesn't elsewhere).
That philosophers arguing about how the brain works (or any other question about what is going on out there) is fruitless, is not something I needed cog-sci to tell me. Philosophers have been warning against philosophizing when we should just go out there and look, for centuries. Those philosophers that involved themselves in classical conceptual analysis in the way you described, did not fail in that they failed to look at cog-sci; they failed in that they couldn't tell that that was not philosophy time, it was go check the world time; this is a much more general and fundamental mistake class than failing to update on a new piece of evidence.
I like philosophy as loosely cog-sci + maths (at least the epistemological/ontological/logic-ish parts). But I would prefer to add to it the normative part of philosophy. Not how do we reason most often (a question at least as psychological as it is philosophical, if not more), but also what is the best, least error prone, fastest, way to reason? (Psychology tells us how we reason/think, but it doesn't know a damn thing about how we should reason/think.) This is not an unassailable field. We could use the tools we develop in Bayes and Calculus to do much of this work deductively. Modern Bayesian epistemology is already moving in this direction. I might also add to philosophy the contrasting and bridging of how we should reason to how we actually do. Of course, this is not to say that that is all philosophy is. Many philosophers have also been interested in forming descriptions of the way things are put together out there, in the most general sense of the terms, e.g., the field of metaphysics. But anyone who is working in ontology, epistemology, and logic, on both the normative and descriptive parts is likely a philosopher.
so to summarize:
How we reason/think is the domain of Psychology/cog-Philosophy/Philosophy of science. How we should reason/think is the domain of logic/epistemology/ontology/Philosophy of science. Getting from how we do reason/think, to how we should reason/think, is the domain of general philosophy/rationalism. Formulating as complete as possible a cohesive, qualitative, general, and abstract description of reality using as divers a range of information as is available, is the domain of metaphysics.
I do admit however that of all of these fields which I think of as essentially intertwined, Psychology is the only one which appears on the list which is not traditionally thought of as philosophical. This motivates me to further investigate philosophy's relationship to psychology.
I am a philosophy major; and I think of myself as a philosopher. But maybe we should just say that philosophy is a dead field; and "philosophy" a hopelessly vague and outdated 2000+ year old term; but many of its tenants, open questions, and methods, survive (normally in some improved form) in the modern field of LW style rationality.
And BTW: I don't see why you can't just say that an item which satisfies some but not all of the necessary conditions for membership in C, is C-ish; the more it has, the C-isher it is; if it has all of them, it is as C-ish as possible, and if it has none it is completely non-C-ish. This seems to capture both the typicality and Aristotelian categorical views as one hypothesis containing both types of categories and inference. Is there anything in cognitive science to suggest that the brain's categories don't function like that? The term you use to refer to some set of necessary conditions need not be the term you use to refer to that set of conditions next week; as long as any category you use consistently follows the rules described above, for as long as it remains consistent. I'm sure someone else has proposed a similar enough idea, anyone know its name?
Philosophy in the Flesh, by George Lakoff and Mark Johnson, opens with a bang:
So what would happen if we dropped all philosophical methods that were developed when we had a Cartesian view of the mind and of reason, and instead invented philosophy anew given what we now know about the physical processes that produce human reasoning?
Philosophy is a diseased discipline, but good philosophy can (and must) be done. I'd like to explore how one can do good philosophy, in part by taking cognitive science seriously.
Conceptual Analysis
Let me begin with a quick, easy example of how cognitive science can inform our philosophical methodology. The example below shouldn’t surprise anyone who has read A Human’s Guide to Words, but it does illustrate how misguided thousands of philosophical works can be due to an ignorance of cognitive science.
Consider what may be the central method of 20th century analytic philosophy: conceptual analysis. In its standard form, conceptual analysis assumes (Ramsey 1992) the “classical view” of concepts, that a “concept C has definitional structure in that it is composed of simpler concepts that express necessary and sufficient conditions for falling under C.” For example, the concept bachelor has the constituents unmarried and man. Something falls under the concept bachelor if and only if it is an unmarried man.
Conceptual analysis, then, is the attempt to examine our intuitive concepts and arrive at definitions (in terms of necessary and sufficient conditions) that capture the meaning of those concepts. De Paul & Ramsey (1999) explain:
The practice continues even today. Consider the conceptual analysis of knowledge. For centuries, knowledge was considered by most to be justified true belief (JTB). If Susan believed X but X wasn’t true, then Susan couldn’t be said to have knowledge of X. Likewise, if X was true but Susan didn’t believe X, then she didn’t have knowledge of X. And if Susan believed X and X was true but Susan had no justification for believing X, then she didn’t really have “knowledge,” she just had an accidentally true belief. But if Susan had justified true belief of X, then she did have knowledge of X.
And then Gettier (1963) offered some famous counterexamples to this analysis of knowledge. Here is a later counterexample, summarized by Zagzebski (1994):
As in most counterexamples to the JTB analysis of knowledge, the counterexample to JTB arises due to “accidents” in the scenario:
A cottage industry sprung up around these “Gettier problems,” with philosophers proposing new sets of necessary and sufficient conditions for knowledge, and other philosophers raising counter-examples to them. Weatherson (2003) described this circus as “the analysis of knowledge merry-go-round.”
My purpose here is not to examine Gettier problems in particular, but merely to show that the construction of conceptual analyses in terms of necessary and sufficient conditions is mainstream philosophical practice, and has been for a long time.
Now, let me explain how cognitive science undermines this mainstream philosophical practice.
Concepts in the Brain
The problem is that the brain doesn’t store concepts in terms of necessary and sufficient conditions, so philosophers have been using their intuitions to search for something that isn’t there. No wonder philosophers have, for over a century, failed to produce a single, successful, non-trivial conceptual analysis (Fodor 1981; Mills 2008).
How do psychologists know the brain doesn’t work this way? Murphy (2002, p. 16) writes:
But before we get to Rosch, let’s look at a different experiment:
Category-membership for concepts in the human brain is not a yes/no affair, as the “necessary and sufficient conditions” approach of the classical view assumes. Instead, category membership is fuzzy.
Another problem for the classical view is raised by typicality effects:
So people agree that some items are more typical category members than others, but do these typicality effects manifest in normal cognition and behavior?
Yes, they do.
(If you want further evidence of typicality effects on cognition, see Murphy [2002] and Hampton [2008].)
The classical view of concepts, with its binary category membership, cannot explain typicality effects.
So the classical view of concepts must be rejected, along with any version of conceptual analysis that depends upon it. (If you doubt that many philosophers have done work dependent on the classical view of concepts, see here).
To be fair, quite a few philosophers have now given up on the classical view of concepts and the “necessary and sufficient conditions” approach to conceptual analysis. And of course there are other reasons that seeking definitions stipulated as necessary and sufficient conditions can be useful. But I wanted to begin with a clear and “settled” case of how cognitive science can undermine a particular philosophical practice and require that we ask and answer philosophical questions differently.
Philosophy by humans must respect the cognitive science of how humans reason.
Next post: Living Metaphorically
Previous post: When Intuitions Are Useful
References
Battig & Montague (1969). Category norms for verbal items in 56 categories: A replication and extension of the Connecticut category norms. Journal of Experimental Psychology Monograph, 80 (3, part 2).
Gettier (1963). Is justified true belief knowledge? Analysis, 23: 121-123.
De Paul & Ramsey (1999). Preface. In De Paul & Ramsey (eds.), Rethinking Intuition. Rowman & Littlefield.
Fodor (1981). The present status of the innateness controversy. In Fodor, Representations: Philosophical Essays on the Foundations of Cognitive Science. MIT Press.
Hampton (2008). Concepts in human adults. In Mareschal, Quinn, & Lea (eds.), The Making of Human Concepts (pp. 295-313). Oxford University Press.
McCloskey and Glucksberg (1978). Natural categories: Well defined or fuzzy sets? Memory & Cognition, 6: 462–472.
Mervis, Catlin & Rosch (1976). Categorization of natural objects. Annual Review of Psychology, 32: 89–115.
Mervis & Pani (1980). Acquisition of basic object categories. Cognitive Psychology, 12: 496–522.
Mills (2008). Are analytic philosophers shallow and stupid? The Journal of Philososphy, 105: 301-319.
Murphy (2002). The Big Book of Concepts. MIT Press.
Murphy & Brownell (1985). Category differentiation in object recognition: Typicality constraints on the basic category advantage. Journal of Experimental Psychology: Learning, Memory, and Cognition, 11: 70–84.
Posner & Keele (1968). On the genesis of abstract ideas. Journal of Experimental Psychology, 77: 353–363.
Rips (1975). Inductive judgments about natural categories. Journal of Verbal Learning and Verbal Behavior, 14: 665–681.
Ramsey (1992). Prototypes and conceptual analysis. Topoi 11: 59-70.
Rips, Shoben, & Smith (1973). Semantic distance and the verification of semantic relations. Journal of Verbal Learning and Verbal Behavior, 12: 1–20.
Rosch (1975). Cognitive representations of semantic categories. Journal of Experimental Psychology: General, 104: 192–233.
Rosch, Simpson, & Miller (1976). Structural bases of typicality effects. Journal of Experimental Psychology: Human Perception and Performance, 2: 491–502.
Smith, Balzano, & Walker (1978). Nominal, perceptual, and semantic codes in picture categorization. In Cotton & Klatzky (eds.), Semantic Factors in Cognition (pp. 137–168). Erlbaum.
Weatherson (2003). What good are counterexamples? Philosophical Studies, 115: 1-31.