All of us have beliefs about the world.  Through our five senses, we gain knowledge about the world and make conclusions from what we have learned.  Our constructed beliefs about the world, though, come as a result of how we think.  Our thinking processes affect our world-views just as much (if not more so) as the knowledge we gain about the world.  Yet, we all think in different – sometimes drastically different – ways.

Skeptics, True Believers and Everything in Between
In his 1998 book Skeptics & True Believers: The Exhilarating Connection Between Science & Religion,[2] Stonehill College physics professor Chet Raymo describes “two intellectual postures [that] we can adopt to questions of knowledge and belief” (2-3).  He calls these archetypes (surprise, surprise) “Skeptics” and “True Believers.”

While Raymo’s classifications are a good start to understanding the difference between skeptics and non-skeptics, I think it might be better to array skepticism into a spectrum, as I describe in my aforementioned article.

 vacant skepticism  moderate skepticism  absolute skepticism

 What I call absolute skepticism is the same as philosophical skepticism, an ancient school of thought that dates back to classical Greece.  This skeptical extreme represents an infinitely skeptical attitude.  If that sounds silly to most people, there actually is some good reason behind it.  The argument goes a little something like this:

- To know something is true, you must know it for certain.
- We humans are not omniscient, so we can never know anything for certain. 
- Therefore, we can never know if something is true (let alone any truths).

The uncertainty of truth led Socrates to say, “All I know is that I know nothing.”  However valid the argument may be, absolute skepticism is very limited in its worldview and represents an eternally closed mind.  If you never allow yourself to believe anything, then you can never really learn anything about or function in the world.  So, absolute skepticism is an unviable position.

If absolute skepticism doesn’t let you believe anything, vacant skepticism let’s you believe everything.  Doubting nothing at all leaves one extremely credulous to any idea – no matter how improbable – as being true.  Moreover, truth becomes plastic so that whatever you believe is true is therefore true.  One of the primary problems with this type of thinking, though, is that it leads one to believe contradictions and impossibilities.  As a result, you can never learn anything meaningful or useful about the world.  So, vacant skepticism is also an unfeasible position.

In the middle, however, is moderate skepticism, which practices reasonable doubt.  Moderate skepticism is the delicate balance between continuous doubt and wide-open credulity, although that’s not as easy at is seems.  Most of us fall in between the two extremes but we don’t necessarily land in the middle.  Raymo’s True Believers lie between vacant and moderate skepticism and most people lie in that area of skepticism than any other.  Self-proclaimed Skeptics, on the other hand, lie just around the middle and towards absolute skepticism.  As any good skeptic knows, it’s hard to be a good skeptic.

So far, I’ve used the terms “skeptic” and “skepticism” quite loosely.  Before we go on to identifying some of the principles of skepticism, it would be beneficial to have a good working definition of what moderate skepticism (heretofore, just “skepticism”) is.

Revealing Untruths
Modern skepticism is different from the ancient skepticism of Socrates, as mentioned above.  So what exactly is skepticism?

According to the Skeptics Society in Altadena, CA, “Skepticism is a provisional approach to claims. It is the application of science to any and all ideas – no sacred cows allowed. In other words, skepticism is a method, not a position. Ideally skeptics do not go into an investigation closed to the possibility that a phenomenon might be real or that a claimant might be right. When we say we are ‘skeptical’ we mean that we must see evidence before we believe. Skeptics are from Missouri – the ‘show me’ state.”[3] [Emphasis added.]  While this is not so much a definition of skepticism as it is a description, it does gives us some clue to what skeptics mean by skepticism: it’s a provisional, methodological application of scientific thinking.

But let’s be a bit more specific.  In his new book, Tales of the Rational, University of Tennessee biologist Massimo Pigliucci defines skepticism as follows: 

Skepticism “is not a theory of knowledge, but rather a way to reveal that which is untrue…A more modern way to think about skepticism is in scientific-statistical terms, as probabilities to commit one of the two fundamental types of errors: rejecting conclusions that are in fact correct (extreme skepticism) or accepting conclusions that are false (extreme gullibility).”[4] [Emphasis added.]

In short, Pigliucci has hit the nail on the head: skepticism is not about discovering truths; instead, it is a method for revealing falsehoods.  Generally speaking, skeptics search for truths by weeding out these falsehoods instead of discovering those truths directly.  However, as Pigliucci points out, mistakes can be made, namely Type I and Type II errors.

Found in the language of statistics, a Type I error is made when rejecting a truth as being false and a Type II error is accepting a falsehood as being true.  We all make Type I errors and Type II errors all the time, simply because we are not omniscient and are limited in our knowledge of the world.  In a perfect world, we would want to reduce the number of both error types; however, this is not always possible.  What the skeptic does is to reduce one of the two error types: Type II errors.  The reasoning for doing so goes likes this: Since there is only one world, there are a greater number of falsehoods about the world than there are truths.  Therefore, skeptics prefer to make Type I errors than Type II errors (i.e., they are the lesser of two evils).  So, skeptics take a chance in making Type I errors so they won’t make Type II errors.

Now that we understand how skeptics think in general, I’ll now discuss some of the basic building blocks of skeptical thought.

Part 2