- Wherever possible there must be independent confirmation of the “facts.”
- Encourage substantive debate on the evidence by knowledgeable proponents of all points of view.
- Arguments from authority carry little weight — “authorities” have made mistakes in the past. They will do so again in the future. Perhaps a better way to say it is that in science there are no authorities; at most, there are experts.
- Spin more than one hypothesis. If there’s something to be explained, think of all the different ways in which it could be explained. Then think of tests by which you might systematically disprove each of the alternatives.
- Try not to get overly attached to a hypothesis just because it’s yours. It’s only a way station in the pursuit of knowledge. Ask yourself why you like the idea. Compare it fairly with the alternatives. See if you can find reasons for rejecting it. If you don’t, others will.
- If whatever it is you’re explaining has some measure, some numerical quantity attached to it, you’ll be much better able to discriminate among competing hypotheses. What is vague and qualitative is open to many explanations.
- If there’s a chain of argument, every link in the chain must work (including the premise) — not just most of them.
- Occam’s Razor. This convenient rule-of-thumb urges us when faced with two hypotheses that explain the data equally well to choose the simpler. Always ask whether the hypothesis can be, at least in principle, falsified…. You must be able to check assertions out. Inveterate skeptics must be given the chance to follow your reasoning, to duplicate your experiments and see if they get the same result.
Carl Sagan's 8 Tools For Critical Thinking
One of the important 21st century skills for any learner, of any age, is critical thinking. Critical thinking as defined by the Oxford Dictionary: Objective analysis and evaluation of an issue in order to form a judgment:professors often find it difficult to encourage critical thinking amongst their students We all know how incredibly difficult it has become to detect whether a news story is factual and unbiased. With the ever increasing number of amateur bloggers and the pressure on journalists to get as many stories out as possible to get views and clicks, the quality if reporting has decreased. Unfortunately, our skepticism has not increased as we have become quick on the trigger finger to share before reading and evaluating the content. In our daily lives, it is not in our nature to think scientifically when faced with what Carl Sagan has called, “society’s most shameless untruths and outrageous propaganda.” It's no wonder that sites like Snopes have emerged to help us filter through what is fact and what is fiction. In his book, The Fine Art of Baloney Detection, Sagan has provided us with a set of "tools for skeptical thinking" which he defines as “the means to construct, and to understand, a reasoned argument and—especially important—to recognize a fallacious or fraudulent argument.” You can see his list of all eight tools, slightly abridged, below (thanks to Open Culture). These are all in Sagan’s words: