Readers will encounter quite a bit about skepticism on this site, and may wonder why. Skeptical investigations of the Shroud of Turin and faith healers are obviously relevant, but what do skeptical investigations of astrology, psychics, and UFOs have to do with atheism? Why bother with explanations about how to be skeptical, how to apply critical thinking, and how to examine arguments to determine if they are logically valid?
Skepticism is part of modern science, basing conclusions on logic, reason, and evidence. It is a method which leads to reliable conclusions rather than a conclusion itself. Atheism, when based on critical thinking and reason, is a form of skepticism that is directed at a particular area of belief. George Smith argues that a reasonable person's atheism should be based on what he calls a "habit of reasonableness." Atheists should get in the habit of using reason to evaluate claims ? we shouldn't let emotions or desires push us in one direction or the other and we shouldn't make exceptions for favored ideas.
Reasonable skepticism is an essential basis of Freethought, or the idea that decisions about religion should be made independently and without relying on the demands of either authority or tradition. It is not the ultimate conclusions which are being described, but instead the method of arriving at those conclusions. Atheists should strive to consistently employ a methodology of naturalism, skepticism, and empiricism ? not just where religion and theism are concerned, but broadly in all areas of life.
Reason vs. Mysticism
An essential tension which arises in society is that between reason and mysticism ? and this is a tension which both skeptics and atheists must face. Skepticism, atheism, and science stand on the side of reason while religious, supernatural, and paranormal beliefs stand on the side of mysticism. Thus while skeptics are not all necessarily atheists, skeptics and atheists should regard each other as natural allies in the effort to promote reason, critical thinking, and naturalism in society.
The mystical outlook which is so common today involves basing broad conclusions upon personal insights to the exclusion or even detriment of external, empirical validation. Although there is nothing inherently wrong with personal insights, they do not become objective and should not be considered "truth" unless and until they are confirmed via external validation.
Science and skepticism, on the other hand require that conclusions be based upon logical arguments and verifiable evidence ? the more evidence you have, the more reliable you can regard the conclusion and the more firmly you can justify believing it. Skeptics and atheists do not reject personal insights out of hand, but they should not treat those insights as "truth" merely upon the word of an individual or the strength of a personal experience. Truth is much too serious and important a matter to be treated so shabbily.
Skeptics and atheists face another common problem: the high level of credulity in the general population. Strange tales which ensnare gullible people are legion in our society. Turn on the TV and you'll find at least a dozen shows devoted to promoting the idea that certain events cannot have a natural, mundane explanation. At the same time, though, you'll hardly find any which are devoted to seriously and honestly looking for natural, verifiable causes. Skepticism ? about anything ? simply does not sell well. It's not sensationalistic enough for our media. Fables presented uncritically will attract more viewers and adherents than a sober and balanced treatment.
Broadening Skepticism to Religion & Theism
The application of skepticism has commonly been limited to specific claims about paranormal or miraculous events. Skeptics rarely take on fundamental religious claims directly, and certainly not within bounds of their normal skeptical investigations. I, however, find any such a division to be artificial and without significant merit. Skepticism towards claims about astrology and psychic healers should go hand in hand with skepticism towards the claim that gods exist or that I am a sinner in need of salvation.
All of these and similar claims are on a relatively equal level in terms of credibility and reliability. There is little discernible difference between witnesses who allege to have seen UFOs and witnesses who allege to have seen angels, demons, or saints. Some claim to have been told what they must do by aliens, others by their god. What reason could there be for approaching religious claims any differently than paranormal claims? It is interesting how often religious believers reject paranormal claims without noticing the similarities between those beliefs and their own.
The reasons that I am a skeptic are same as why I am a humanist and an atheist. I treat religious and supernatural claims much like I treat paranormal claims and am willing to examine both the claims being made and the evidence offered in support of them. So far, none have managed to stand up under critical inquiry.