A clear, comprehensive and concise definition of skepticism.

[scienceteacherinexile]

steveweiss
Your points seem very rhetorical to me.
Instead of "a clear, comprehensive and concise definition" of skepticism, maybe we should go for "a clear, concise, and usable definition".
Trying to get in deep with the philosophy of skepticism to ensure it is comprehensively defined does not interest me.  A straight forward definition gives you something to work with and define action points.
For example, I have been a frequent visitor to the Committee for Skeptical Inquiry for years.  They were the Committee for the Scientific Investigation of Claims of the Paranormal.  They publish the Skeptical Inquirer magazine and the following is from their website:

The Committee for Skeptical Inquiry encourages the critical investigation of paranormal and fringe-science claims from a responsible, scientific point of view and disseminates factual information about the results of such inquiries to the scientific community and the public. It also promotes science and scientific inquiry, critical thinking, science education, and the use of reason in examining important issues. To carry out these objectives the Committee:


Maintains a network of people interested in critically examining paranormal, fringe science, and other claims, and in contributing to consumer education

Prepares bibliographies of published materials that carefully examine such claims

Encourages research by objective and impartial inquiry in areas where it is needed

Convenes conferences and meetings

Publishes articles that examine claims of the paranormal

Does not reject claims on a priori grounds, antecedent to inquiry, but examines them objectively and carefully
The Committee is a nonprofit scientific and educational organization, started in 1976. The Skeptical Inquirer is its official journal.

Some of the founding members of CSI include scientists, academics, and science writers such as Carl Sagan, Isaac Asimov, Philip Klass, Paul Kurtz, Ray Hyman, James Randi, Martin Gardner, Sidney Hook, and others. A list of CSI fellows is published in every issue of Skeptical Inquirer magazine.

That does not contain a detailed description of skeptics, but it has some really useful characteristics of the skeptic in there.
Depending on the purpose of defining skeptic, it is more meaningful than reducing the meaning down to "you do not believe in anything".

[bluegray V]

Ok, you first. What is your clear, concise, and usable definition?

[scienceteacherinexile]

Let me think it over.  I do not have one devised yet, I just thought the quote from CSI contained a few things we could discuss, include, modify or discard. I like your definition fine although it should not be necessary to distinguish skepticism from cynicism.  Should not, but I know why it is necessary sometimes.
Using parts I like from CSI in particular we could say something like:
 A skeptic uses "scientific inquiry, critical thinking, science education, and the use of reason in examining important issues."  I would also have something in the definition about being rational...
I think it should have something about the view of the skeptic on the supernatural, but haven't got the phrasing yet.
Any help?

[scienceteacherinexile]

bluegray,
This weekend I was commenting over at a blog on scienceblogs.com because it had a South African basis.  It was basically about Mbeki being a denialist on HIV/AIDS.  To make a long story longer, I am an American who has has lived here for over 9 years, and most of the commenters are American, but do not have the direct experience as I do with South African health services and politics, etc.. 
The point is, there was a heinous thread jacking that took place there by HIV denialists.  They like to call themselves "skeptics".  So, I think our definition should somehow distiguish ourselves from denialists.  Not sure how to do that, but just putting out that suggestion.

[bluegray V]

The point is, there was a heinous thread jacking that took place there by HIV denialists.  They like to call themselves "skeptics".  So, I think our definition should somehow distiguish ourselves from denialists.  Not sure how to do that, but just putting out that suggestion.

I think it already does.
My brief description on the main page, Luthon's much more eloquent definition and the quote from CSI you posted all share one thing. Claims and ideas are evaluated using the tools of science and critical thinking. There will always be skeptics that don't share this view and discard evidence or deny ideas without proper investigation or critical analysis.
People have tried before to distance themselves from these kind of skeptics by inventing new terms for modern skepticism, Brights, freethinkers etc. I use the term skeptic because I mostly agree with the current skeptic movement, even though the term has it's problems. As a skeptic I am part of other skeptical movements, and while our goals may not be the same, our method of evaluating claims and ideas are.

If an AIDS denialist believes an idea against proper evidence, he can call himself whatever he wants. His methods of evaluating ideas (or lack thereof) will reveal him as someone that surely does not share this skeptic's view.

PS. Please start a separate AIDS denialist thread. I would like to discuss this topic, but do not know enough about it.