I think "skepticism" can refer to multiple different things, and my answers to the above questions differ in some cases depending on how the term is being used. It can refer to philosophical skepticism, to scientific skepticism, to "skeptical inquiry," to "doubt" broadly speaking, to the "skeptical movement," to skeptical organizations, and to members of the class of people who identify themselves as skeptics.
My quick answers to the above questions, then, are:
Does skepticism imply atheism? No, regardless of which definition you choose. It is reasonable to argue that proper application of philosophical skepticism should lead to atheism, and to argue that scientific skepticism should include methodological naturalism, but I prefer to identify skepticism with a commitment to a methodology rather than its outputs. That still involves a set of beliefs--which are themselves subject to reflection, criticism, and evaluation--but it is both a more minimal set than the outputs of skepticism and involves commitment to values as well as what is scientifically testable. My main opposition to defining skepticism by its outputs is that that is a set of beliefs that can change over time with access to new and better information, and shouldn't be held dogmatically.
Are "climate change skeptics" skeptics? I would say that some are, and some aren't--some are outright "deniers" who are allowing ideology to trump science and failing to dig into the evidence. Others are digging into the evidence and just coming to (in my opinion) erroneous conclusions, but that doesn't preclude them from being skeptics so long as they're still willing to engage and look at contrary evidence, as well as admit to mistakes and errors when they make them--like relying on organizations and individuals who are demonstrably not reliable. As you'll see below, I agree we should to try to save the term "skeptic" from being equated with denial.
Must skeptics defer to scientific consensus or experts? I think skeptical organizations and their leaders should defer to experts on topics outside of their own fields of expertise on pragmatic and ethical grounds, but individual skeptics need not necessarily do so.
Should skepticism as a movement or skeptical organizations restrict themselves to paranormal claims, or avoid religious or political claims? I think skepticism as a movement, broadly speaking, is centered on organizations that promote scientific skepticism and focus on paranormal claims, but also promote science and critical thinking, including with some overlap with religious and public policy claims, where the scientific evidence is relevant. At its fringes, though, it also includes some atheist and rationalist groups that take a broader view of skeptical inquiry. I think those central groups (like CSI, JREF, and the Skeptics Society) should keep their focus, but not as narrowly as Daniel Loxton suggests in his "Where Do We Go From Here?" (PDF) essay.
Here are a few of my comments, on these same topics, from other blogs.
Comment on Michael De Dora, "Why Skeptics Should be Atheists," at the Gotham Skeptic blog:
Scientific skepticism (as opposed to philosophical skepticism) no more necessitates atheism than it does amoralism. Your argument would seem to suggest that skeptics shouldn’t hold any positions that can’t be established by empirical science, which would seem to limit skeptics to descriptive, rather than normative, positions on morality and basic (as opposed to instrumental) values.
“Skepticism” does have the sort of inherent ambiguity that “science” does, in that it can refer to process, product, or institution. I favor a methodological view of skepticism as a process, rather than defining it by its outputs. Organizations, however, seem to coalesce around sets of agreed-upon beliefs that are outputs of methodology, not just beliefs about appropriate/effective methodology; historically that set of agreed-upon beliefs has been that there is no good scientific support for paranormal and fringe science claims. As the scope of skeptical inquiry that skeptical organizations address has broadened, that leads to more conflict over issues in the sphere of politics and religion, where empirical science yields less conclusive results.
I’d rather see skeptical organizations share some basic epistemic and ethical values that are supportive of the use of science than a commitment to a set of beliefs about the outputs of skeptical methodology. The latter seems more likely to result in dogmatism.
Comment on Daniel Loxton, "What, If Anything, Can Skeptics Say About Science?" at SkepticBlog:
Comment on jdc325's "The Trouble With Skeptics" at the Stuff And Nonsense blog:
While I think the picture Daniel presents offers some good heuristics, I can’t help but note that this is really proffered normative advice about the proper relationship between the layman and the expert, which is a question that is itself a subject of research in multiple domains of expertise including philosophy of science, science and technology studies, and the law. A picture much like the one argued for here is defended by some, such as philosopher John Hardwig (”Epistemic Dependence,” Journal of Philosophy 82(1985):335-349), but criticized by others, such as philosopher Don Ihde (”Why Not Science Critics?”, International Studies in Philosophy 29(1997):45-54). There are epistemological, ethical, and political issues regarding deference to experts that are sidestepped by the above discussion. Not only is there a possibility of meta-expertise about evaluating experts, there are cases of what Harry Collins and Robert Evans call “interactional expertise” (”The Third Wave of Science Studies: Studies of Expertise and Experience,” Social Studies of Science 32:2(2002):235-196) where non-certified experts attain sufficient knowledge to interact at a deep level with certified experts, and challenge their practices and results (this is discussed in Evan Selanger and John Mix, “On Interactional Expertise: Pragmatic and Ontological Considerations,” Phenomenology and the Cognitive Sciences 3:2(2004):145-163); Steven Epstein’s book Impure Science: AIDS, Activism, and the Politics of Knowledge, 1996, Berkeley: Univ. of California Press, discusses how AIDS activists developed such expertise and successfully made changes to AIDS drug research and approval processes.
The above discussion also doesn’t discuss context–are these proposed normative rules for skeptics in any circumstance, or only for those speaking on behalf of skeptical organizations? I don’t think it’s reasonable to suggest that skeptics, speaking for themselves, should be limited about questioning anything. The legal system is an example of a case where experts should be challenged and questioned–it’s a responsibility of the judge, under both the Frye and Daubert rules, to make judgments about the relevance and admissibility of expert testimony, and of laymen on the jury to decide who is more credible. (This itself raises enormous issues, which are discussed at some length by philosopher and law professor Scott Brewer, “Scientific Expert Testimony and Intellectual Due Process,” The Yale Law Journal vol. 107, 1535-1681.) Similar considerations apply to the realm of politics in a democratic society (cf. Ihde’s article).
All of the papers I’ve cited are reprinted in the volume The Philosophy of Expertise, edited by Evan Selinger and Robert P. Crease, 2006, N.Y.: Columbia University Press.
@AndyD I’d say that it’s possible for a skeptic to believe individual items on your list (though not the ones phrased like “the entirety of CAM”), so long as they do so because they have legitimately studied them in some depth and think that the weight of the scientific evidence supports them, or if they admit that it’s something they buy into irrationally, perhaps for the entertainment it brings or to be part of a social group. If, however, they believe in a whole bunch of such things, that’s probably evidence that they’re not quite getting the point of critical thinking and skepticism somewhere. Being a skeptic doesn’t mean that you’re always correct (as per the above comment on Skeptic Fail #7), and I don’t think it necessarily means you’re always in accord with mainstream science, either.Comments (one and two) on "Open Thread #17" at Tamino's Open Mind blog:
Skeptic fail #6 is a pretty common one. For example, I don’t think most skeptics have a sufficient knowledge of the parapsychology literature to offer a qualified opinion, as opposed to simply repeat the positions of some of the few skeptics (like Ray Hyman and Susan Blackmore) who do.
Ray Ladbury: I think you’re in a similar position as those who want to preserve “hacker” for those who aren’t engaged in criminal activity. I understand and appreciate the sentiment, but I think “skeptic” already has (and, unlike “hacker,” has actually always had) common currency in a much broader sense as one who doubts, for whatever reason.
I also think that there are many skeptics involved in the organized and disorganized skeptical movement in the U.S. (the one started by CSICOP) who don’t meet your criteria of “sufficiently knowledgeable about the evidence and theory to render an educated opinion” even with respect to many paranormal and pseudoscience claims, let alone with respect to climate science. There’s an unfortunately large subset of “skeptics” in the CSICOP/JREF/Skeptics Society sense who are also climate change skeptics or deniers, as can be seen from the comments on James Randi’s brief-but-retracted semi-endorsement of the Oregon Petition Project at the JREF Swift Blog and on the posts about climate science at SkepticBlog.org.
Ray: You make a persuasive argument for attempting to preserve “skeptic.” Since I’ve just been defending against the colloquial misuse of “begs the question,” I think I can likewise endorse a defense of “skeptic” against “pseudoskeptic.” However, I think I will continue to be about as reserved in my use of “denier” as I am in my use of “liar.” I don’t make accusations of lying unless I have evidence not just that a person is uttering falsehoods, but that they’ve been presented with good evidence that they are uttering falsehoods, and continue to do so anyway.
On another subject, I’d love to see an equivalent of the Talk Origins Archive (http://www.talkorigins.org/), and in particular Mark Isaak’s “Index to Creationist Claims” (http://www.talkorigins.org/indexcc/list.html) for climate science (and its denial). Do they already exist?
"Massimo Pigliucci on the scope of skeptical inquiry" (October 21, 2009)
"Skepticism, belief revision, and science" (October 21, 2009)
Also, back in 1993 I wrote a post to the sci.skeptic Usenet group that gave a somewhat oversimplified view of "the proper role of skeptical organizations" which was subsequently summarized in Michael Epstein's "The Skeptical Viewpoint," Journal of Scientific Exploration, vol. 7, no. 3, Fall 1993, pp. 311-315.
UPDATE (January 7, 2010): Skepdude has taken issue with a couple of points above, and offers his contrary arguments at his blog. First, he says that skeptics need to defer to scientific consensus with the "possible exception" of cases where "the person is also an expert on said field." I think that case is a definite, rather than a possible exception, but would go farther--it's possible to be an expert (or even just a well-informed amateur) in a field that has direct bearing on premises or inferences used by experts in another field where one is not expert. That can give a foothold for challenging a consensus in a field where one is not expert. For example, philosophers, mathematicians, and statisticians can spot errors of conceptual confusion, fallacious reasoning, invalid inferences, mathematical errors, and misuse of statistics. It's possible for an entire field to have an erroneous consensus, such as that rocks cannot fall from the sky or continents cannot move. I suspect an argument can be made that erroneous consensus is more likely to occur in a field with a high degree of specialization that doesn't have good input from generalists and related fields.
I also am uncomfortable with talk of "deference" to experts without scope or context, as it can be taken to imply the illegitimacy of questioning or demanding evidence and explanation in support of the consensus, which to my mind should always be legitimate.
The second point is one which Skepdude and I have gone back and forth on before, both at his blog (here, here, and here -- I could have used these comments as well in the above post) and via Twitter, which is about whether skepticism implies (or inevitably leads) to atheism. It's a position which I addressed above in my comments on Michael De Dora and on the "Stuff and Nonsense" blog, though he doesn't directly respond to those. He writes:
I fail to see the distinction between skepticism implying atheism and proper application of skepticism leading to atheism. I regard the two as saying the same thing, that skepticism, if consistently applied should lead to atheism. I am not sure what Jim means by philosophical skepticism, and maybe that’s where he draws the difference, but I refrain from using qualifiers in front of the word skepticism, be it philosophical or scientific. Skepticism is skepticism, we evaluate if a given claim is supported by the evidence.There is most definitely a distinction between "skepticism implies atheism" and "proper application of skepticism leads to atheism." The former is a logical claim that says atheism is derivable from skepticism, or that it's necessarily the case that the use of skepticism (regardless of inputs?) yields atheism. The latter is a contingent claim that's dependent upon the inputs and the result of the inquiry. If skepticism is defined as a method, the former claim would mean in essence that the game is rigged to produce a particular result for an existence claim necessarily, which would seem to me to be a serious flaw in the method, unless you thought that atheism was logically necessary. But I'm not aware of any atheists who hold that, and I know that Skepdude doesn't, since he prefers to define atheism as mere lack of belief and has argued that there is no case to be made for positive atheism/strong atheism.
If we take skepticism defined as a product, as a set of output beliefs, there's the question of which output beliefs we use. Some idealized set of beliefs that would be output from the application of skeptical processes? If so, based on which set of inputs? In what historical context? The sets of inputs, the methods, and the outputs all have changed over time, and there is also disagreement about what counts as appropriately well-established inputs and the scope of the methods. The advocate of scientific skepticism is going to place more constraints on what is available as input to the process and the scope of what the process can deal with (in such a way that the process cannot be used even to fully evaluate reasons for being a skeptic, which likely involve values and commitments that are axiomatic or a priori). Methodological naturalism is likely to be part of the definition of the process, which means that theism cannot be an output belief--I think this is probably what Skepdude means when he says that atheism defined as a lack of belief is a product of skepticism. But note that the set of output beliefs from this process is a subset of what it is reasonable to believe, unless the advocate of this view wants to assert that the commitment to skepticism itself is not reasonable to believe--in virtue of the fact that it is not subject to a complete evaluation by the process. (As an aside, I think that it is possible for the process of skepticism thus defined to yield a conclusion of its own inadequacy to address certain questions, and in fact, that if we were to observe certain things, to yield the conclusion that methodological naturalism should be rejected.)
If we look at skepticism more broadly, where philosophical arguments more generally are acceptable as input or method, atheism (in the positive or strong form) then becomes a possible output. As an atheist, I think that use of the best available evidence and arguments and the best available methodology does lead to a conclusion of atheism (and 69.7% of philosophy faculty and Ph.D.s agree), that still doesn't mean that everyone's going to get there (as 69.3% of philosophy faculty and Ph.D.s specializing in philosophy of religion don't) or that anyone who doesn't has necessarily done anything irrational in the process, but for a different reason than in the prior case. That reason is that we don't function by embodying this skeptical process, taking all of our input data, running it through the process, and believing only what comes out the other side. That's not consistent with how we engage in initial learning or can practically proceed in our daily lives. Rather, we have a vast web of beliefs that we accumulate over our lifetimes, and selectively focus our attention and use skeptical processes on subsets of our beliefs. The practical demands of our daily lives, of our professions, of our social communities, and so forth place constraints on us (see my answers to questions in "Skepticism, belief revision, and science"). And even with unlimited resources, I think there are reasons that we wouldn't want everyone to apply skeptical methods to everything they believed--there is value to false belief in generating new hypotheses, avoiding Type I errors, keeping true beliefs from becoming "dead dogma," and so forth (which I discussed in my SkeptiCamp Phoenix presentation last year, "Positive side-effects of misinformation").
UPDATE (January 16, 2009): Skepdude responds here.