Carl Sagan's Famous Baloney Detecting Kit

From Scientificmetho


Near the time of his death, Carl Sagan had serious reservations about our ability as a society to think critically. He stated in one of his last interviews that he feared we may be heading towards "a darker age". This is particularly omnious, considering just how bad he knew the last "dark age " to be.

Some might cast aside Sagan's words as the cynicism of an old, dying man. While a deterioristic viewpoint is not uncommon for older folks, bewildered as they may be by fast changing times, this caricature does not describe Sagan. I believe Carl saw truly that many people in the world were becoming a bit less scientifically skeptical in favor of being more cynical, lazy, and uncritical in their thinking. And he feared what kind of world his grandchildren might grow up in - a world where dogma, "authority" and rhetoric ruled, and where science became something unimportant to the average person - the territory of gray bearded men living in isolated ivory towers.

Because of this, Carl sought to teach people how to be better critical thinkers. He wanted to teach them a bit of how scientists think. He hoped that people might come to be "obsessed with reality, an "insult" one critic once hurled at him. To do this job, Carl explained a bit of how scientists worked:

"Scientists, in order to avoid error (falling for baloney) employ many tools that help them weed out theories that are advanced or supported out of some human need - such as emotional attachment, fear, or greed. In science we may start with experimental results, data, observations, measurements, in short, what the layman would call facts. We invent, if we can, a rich array of possible explanations and systematically confront each explanation with ALL the facts. In the course of their training, scientists are equipped with a Baloney Detection Kit . What is in the kit? Tools for skeptical thinking - means to construct and understand a reasoned argument and to recognize a fallacious or fraudulent argument. Its never a question of whether we like the conclusion that emerges out of a train of reasoning, but whether the conclusion follows from the premises logically."

The tools are as follows(I added the first one, which is implicit in Sagan's work)

The Baloney Detecting Kit


In science, we do not hold to our results with absolute certainty. Instead, we support theories with empirical evidence, and test them by experiments. We attempt to disprove our claims, vigorously and often. Theories that survive this scrutiny are accepted, tenatively. As Karl Popper says: "All theories will eventually be replaced by better ones."

Whenever 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 or no weight. Authorities have been responsible for the biggest of blunders throughout history, and will repeat these errors in the future. In science, there are no authorities, only experts.

Spin more than one hypothesis. If there is something to be explained, think of all the different ways it which it could be explained. Think of tests by which you might systematically disprove each of the alternatives. What survives this Darwinian selection amonng multiple working hypotheses has a better chance of being true. (By the way, THIS is the reason why ideologues are wrong - by definition, they must oppose any other system for arriving at solutions.

Try not to become emotionally attached to a hypothesis just because its yours. Compare it fairly to others. (Again, another reason ideologues are left in the dust)

Quantify. Measurable data are superior to any other kind. Operationalize. What is vague and qualative is open to interpretation, or loop explanations. There are truths to be sought in the many qualitative issues we are obliged to confront, but finding them is always more of a challenge.

If there is a chain of argument, every link in the chain must work, not just most of them. Often, the theorist recognizes this point, but due to the beauty of other areas of the theory, resists change.

Occams Razor. If you are faced with two hypotheses that work equally well, choose the simpler one.

Propositions should be falsifiable. What would prove your hypothesis false? If your hypotheiss is untestable, unfalsifiable, it is not worth much. The more Wiggle room a theory has, the weaker it is. Theories with no falsifiabilty are incapable of predicting events - since, because any outcome supports the theory, any outcome is possible. Skeptics must be allowed to see how a theory works.

Conduct control experiments - especially "double blind" experiments where the person taking measurements is not aware of the test and control subjects.

Check for confounding factors - separate the variables. Factors other than those you are testing may influence results.

Common Fallacies of Logic and Rhetoric

Ad hominem - attacking the arguer and not the argument.


Argument from "authority".

Argument from adverse consequences (putting pressure on the decision maker by pointing out dire consequences of an "unfavourable" decision).


Appeal to ignorance (absence of evidence is not evidence of absence).


Special pleading (typically referring to god's will).

Begging the question (assuming an answer in the way the question is phrased).


Observational selection (counting the hits and forgetting the misses).

Statistics of small numbers (such as drawing conclusions from inadequate sample sizes).

Misunderstanding the nature of statistics (President Eisenhower expressing astonishment and alarm on discovering that fully half of all Americans have below average intelligence!)


Inconsistency (e.g. military expenditures based on worst case scenarios but scientific projections on environmental dangers thriftily ignored because they are not "proved").

Non sequitur - "it does not follow" - the logic falls down.


Post hoc, ergo propter hoc - "it happened after so it was caused by" - confusion of cause and effect.


Meaningless question ("what happens when an irresistible force meets an immovable object?).

Excluded middle (or false dichotomy) - considering only the two extremes in a range of possibilities (making the "other side" look worse than it really is).


Short-term v. long-term - a subset of excluded middle ("why pursue fundamental science when we have so huge a budget deficit?").

Slippery slope - a subset of excluded middle - unwarranted extrapolation of the effects (give an inch and they will take a mile).


Confusion of correlation and causation.


Straw man - caricaturing (or stereotyping) a position to make it easier to attack.


Suppressed evidence or half-truths.

Weasel words - for example, use of euphemisms for war such as "police action" to get around limitations on Presidential powers. "An important art of politicians is to find new names for institutions which under old names have become odious to the public"

Sagan adds: I believe that if you use these methods in your everyday life, you'll come to have a better understanding of your world.

I also forward the interested reader to my more more in depth list of logical fallacies on my logic page at: This list includes all of Sagan's plus many more, and it explains them in depth.

The Baloney Detector Program(tm)

Now that you have some grasp of the scientific method, why not check out your own pet theory? In honor of Carl Sagan, I have made my own Baloney Detector. I used some of the main criteria that he has suggested. Try it out yourself!

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Those taking a tour of the site can now proceed to the next section: Commonly Held Myths About Science

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