Skepticism Made Easy

Doubt as a tool for knowledge

The way to see by faith is to shut the eye of reason.
– Benjamin Franklin, 1758

1. Figure out if a claim is even eligible to be considered "rational".

First of all, you must decide if a claim is eligible to be rational or not. There are, for example, claims that have nothing to do with logic like artistic statements or emotional claims. "Rainbows are pretty,” “I love banjo music," or "that book of Chinese poetry really changed my life" are not rational claims and are thus not subject to rational skepticism as they are not capable of being true or false. In such matters of taste, one can simply respond with “I disagree” and the matter is finished. However, most claims do not fit into this paradigm.

2. Is the claim based on sound evidence and reasoning?

Outside of matters of taste and opinion, most claims are subject to rational skepticism. Typically, these claims are declaring some "fact" or "truth" about the world. When we question the strength of a truth–claim, we are challenging the veracity of the claim (veritas is the Latin word for "truth"). Everyone has reasons (whether they're aware of them or not) for saying what they say. Often they're simply bad reasons. If a claim depends on an error of logic, then it is dead on arrival. So, in order for a person's claim to be considered reasonable, the claimant must show that his claim is based on logic and sound evidence. So, does the claim depend on fallacious reasoning?

  • Appeals to Emotion: I know Senator Smith is right because I can feel it in my gut!
  • Appeals to Authority: But my parents told me that Santa Claus was real!
  • Appeals to Tradition: But that song is part of our heritage! We've always sung it, so it doesn't matter if it’s racist.
  • Special Pleading: No one can really explain how Apollo's chariot drags the sun across the sky. You just have to believe it.
  • Tautology (proving the premise by simply restating it): I'm a Buddhist because I believe that's the best religion for me.
  • Hasty Generalization: The pyramids were built with really heavy stones—they must have been built by aliens!
  • False Dilemma: Either you're a member of the Patriot's Party or you're not a true American!
  • Ancedotal Evidence: My Grandma likes that product, so clinical trials aren't necessary to prove its claims.

If a person must use fallacious thinking to make a claim, then, aside from pointing out the fallacy in his or her thinking, the skeptic generally sees no point in discussing the matter further. Just because a story is "meaningful" to an irrational person doesn't mean that it's "logical.” Sadly, many people have no problem living a life devoid of reason or self–examination. The great majority of the time, a claimant isn't even aware that a claim suffers from fallacious thinking but it does nonetheless end the debate for the skeptic.

3. Ockham's Razor. Always start with the simplest explanation and proceed carefully. (William of Ockham, 1287-1347)

The assertion of the Medieval monk William of Ockham, now known as Ockham's Razor, is often stated as "the simplest explanation is generally the right one." This is not meant to throw out all complex explanations. Rather, Ockham is pointing out that before we succomb to overly complex explanations, we must first soundly disprove simpler explanations. For example, before we assert that the pyramids were built by aliens, we first have to disprove the much simpler likelihood that the pyramids were built by ancient humans (which, by the way, is in no danger of being disproven).

4. Doubt. Assume a claim is false until you find a valid reason not to doubt it. (René Descartes, 1596-1650)

Now regarded as the founder of Modern Philosophy, Descartes heroically put aside the interests of the Medieval Church in the name of rigorous philosophical research. While a proud French Catholic himself, Descartes found the Church's insistence to dogma within philosophy to be detrimental to both the Church as well as to philosophy. By Descartes' time, the Catholic Church had many enemies—Spanish Muslims to the south and German Protestants to the east threatened the very existence of his religious world. So it only made sense for Descartes to seek answers that did not rely on the shaky ground of fallacious appeals to tradition or authority. From that thinking arose the question that separates the Modern world from the Medieval: Of what can we be absolutely certain?

5. Evidence. Extraordinary claims require extraordinary evidence. (David Hume, 1711-1776)

One of David Hume's principle projects was to question the generally recieved knowledge of early modern Europeans. In his 1748 Enquiry Concerning Human Understanding, Hume points to the extraordinary claims of miracles made by the religious figures of his day and asks which is more probable: that this man has been decieved, or that a miracle has occurred against the laws of nature? Skeptics like Hume point out that people are too easily decieved—often without knowing or understanding they've been deceived. Hume also understood claims to be on a sliding scale. That is, simple claims require simple evidence (i.e. to see if it's raining, just look out a window). But when someone makes a claim that goes against centuries of scientific, empirical, evidence–based knowledge of the world, then that person must produce evidence that is, itself, utterly amazing and beyond the sum of all the knowledge that came before it. Such is the standard of proof we set before Galileo, Newton, Darwin, Kepler, and Einstein. And they were certainly equal to the task.

6. Social ConstructivismRecognize that everyone's knowledge of the world is socially–constructed. (Immanuel Kant, 1724-1804)

Immanuel Kant came to realize that none of us has a completely objective view of the world. In fact, what we usually consider pure “observation” entails a synthetic construction of incoming information (through our eyes, ears, etc.) with the experiences we’ve had that have already shaped our way of thinking. So when someone from a different political party, sports team, religion, or country describes his worldview to us, it turns out that neither party in that conversation will have an entirely objective view of the discussion. This is not for lack of trying, but is instead a fundamental epistimological fact: there is no purely objective point–of–view. Always bear in mind that the positions we take are value–laden and subject to our own diverse experiences and educational opportunities.

7. Historical Grounding. Recognize that all of our ideas are products of historical forces. (Michel Foucault, 1926-1984)

One of Michel Foucault’s more interesting observations was our propensity to believe that some things have a “history,” like the United States or slavery, but most things were just naturally unchanging ideas like sexuality or health care. Foucault makes the leap, however, to say that all of our ideas are embedded in histories that are often ignored. The way sexuality was described or questioned 100 years ago has a very different set of assumptions and priorities than when one views sexuality today. Most of the time, we are totally unaware that our ideas are embedded in an almost invisible history. Moreover, this coveringover of history is generally to the benefit of those in charge of such knowledge—such that anyone who later comes along and asks questions is treated with suspicion or contempt. In brief, understand that we are all products of generally unrecognized historical forces. No one stands outside of time. Your questions and positions are just as historically–situated as any one else’s. Skepticism is an historical construction. As is science. And religion. So please make claims with due humility.

8. Model–Dependent RealityClaims find their value in their usefulness, not in their “realness." (Stephen Hawking, born 1942)

All too often, we can get bogged down in the battle between which worldview is the “right” one. Take for example the early modern Copernican question: whether the sun revolves around the earth or the earth around the sun. Of course, almost any modern person would instantly side with the latter claim. And if pressed for an explanation, she would probably say something like, “Well, I say the earth orbits the sun because that's what is really going on.” But this tactic isn’t useful for a scientist like Stephen Hawking. How can we be absolutely sure that’s what’s going on? If our knowledge is constructed (cf. Kant) and even our questions are historically–situated rather than objectively formed (cf. Foucault), how is it that we could ever consider our knowledge to be absolutely true? And, by the way, is that even the role of science? Hawking says no. Hawking maintains that the proper mode of knowledge acquisition is to build a model of what you think reality might look like and test how useful it is in solving problems. In this simple contest, the best model wins. In this way, medieval alchemy is useful until we discover modern chemistry. The idea that disease is spread by putrified air was useful until the discovery of germ theory. And Platonic typology was useful until the discovery of natural selection. In each of these cases, the latter theory simply produces better results than the former theory. What does Hawking mean by “better"? In brief, the newer model of reality is elegant, contains few arbitrary or adjustable elements, takes into account and explains all existing observations, and can make detailed predictions about future observations that could disprove the model if not borne out in future research (that last one marks an important difference between science and pseudoscience!). If the new model of reality is more useful than the old model, then questions about the former model’s “realness” or “rightness" becomes irrelevant. The newer model works better. End of story.

An Example. So: Bob claims that the Earth is held up by an invisible giant sea turtle.

1. Bob is making an ontological claim about reality, so, yes, questions about his claim’s reasonableness are valid. We may proceed.

2. Until Bob says more, we won’t know if he’s guilty yet of committing any logical fallacies. If his next sentence went something like, “now I can’t prove to you that this is the case, but most people take this for granted,” or “now I can’t prove to you that this is the case, you just have to take it on faith,” then he would be guilty of fallacious reasoning (the bandwagon fallacy in the first example, and special pleading in the second one). If, however, he just let the comment stand on its own, then he would be committing the ad hoc fallacy.

3. It’s quite a claim to make that a giant sea turtle is invisible. Wouldn’t it more likely be the case that the giant sea turtle was visible? And why a giant sea turtle? That’s quite an elaborate description. Why not a simpler explaination like, the Earth is held up by some unseen force? Ockham says we have to disprove the simpler explanations before making unnecessarily elaborate ones.

4. Descartes then asks, do I have any good reason to believe Bob’s assertion? Bob may feel he is right, but what evidence is there? It’s not up to me to disprove his claim because doubt is my natural position. Rather, it is very much Bob’s responsibility to prove he is right!

5. Then Hume chimes in. That’s quite an extraordinary claim, Bob! I’ll need more than just your word on this. You’ll need extraordinary evidence to disprove the centuries of scientific findings we have concerning gravity. So, it’s Bob versus NASA. Go!

6. Kant then points out that Bob is talking about sea turtles because his culture values sea turtles. Had Bob come from a culture that had no knowledge of sea turtles, he wouldn’t have made such a claim. Further, any debate about what holds the Earth up stems from the social fact that we moderns hold science up as an arbiter of truth. Bob knows this, and his socialization tells him that if he can cause his audience to question the scientific theory of gravity then we may be more amenable to his sea–turtle–centered–view of reality.

7. Foucault then points out that the use of the ontological contradiction of a "sea turtle" with “invisible” is an historical response to previous disputations involving supernatural responses to logical scrutiny wherein contradiction was the only discursive strategy left open. Or Bob's just making it up because we live in nihilistic times. Either way, Bob’s claims to reality are historically informed.

8. Professor Hawking then shakes his head and says that it doesn’t matter whether or not the Earth is held up by an invisible giant sea turtle. Bob can say whatever he likes. Science has no concern for "the way things really are.” Instead, science is interested in determining which of two competing models of reality is the most useful. So what if Bob says that the Earth is held up by an invisible giant turtle? Sally says that the Earth is “held” by gravitational forces from the sun and moon. Sally’s model of reality not only fits with our modern observations but anticipates specific activities like the tides and the tilt of the Earth's axis. What does Bob’s model of reality anticipate? Absolutely nothing! And that ends the discussion, because if a claim is useless does it matter if it’s real?

David Hume famously admonishes skeptics to commit such sophistry "to the flames" and be done with it. Though had Hume been born in our time, he probably would have asked us simply to delete it from our inbox. Such is the way of the modern skeptic.