(Fallacy of the Beard, Line Drawing Fallacy, Bald Man Fallacy, Fallacy of the Heap, Fallacy of the Grey, the Sorites Fallacy)

This fallacy occurs when someone claims that just because a concept exists on a continuum that there really is no difference between the two ideas at the ends of the continuum. A type of equivocation fallacy (where two different things are presented as the same thing), it is often used as a means of dismissing entire positions by arguing that since not all experts agree or because there is no “100%” consensus, no valid conclusion can be drawn. This is a very common tactic used by science deniers who use outliers in data or misrepresented information as an argument against overwhelming evidence (e.g. global warming, evolution/creation, anti-vaccination) – which is also another fallacy: slothful induction.

This fallacy is the basis behind equating natural selection (science) with social Darwinism (philosophy), environmentalism with eugenics, and abortion with killing newborn children. It’s also a common tactic of moral relativists who try to justify their position by equating it something much worse (or much better): the argument, “Winston Churchill is as bad as Hitler because he allowed over a million people to starve to death in Burma,” ignores the fact that Hitler ordered the extermination of an entire race of people whereas Churchill was trying to fight Hitler and save Nazi-occupied Greece from starvation at the same time as the Bengal famine.

It is also employed when someone uses it to dismiss science because “science has been wrong before.” Science is a self-correcting process; as we gain more knowledge, we refine our understanding of what is “accepted.” Therefore, it is because science admits that it has been wrong in the past that makes science as a process so reliable: widely-accepted principles are only accepted because the vast amount of data we have confirms it.

This fallacy is similar to the slippery slope fallacy, the difference being that the slippery slope fallacy is a causative fallacy (one event automatically leads to the other regardless of the likelihood of it happening; e.g. the legalization of same-sex marriage and bestiality, which ignores informed consent) whereas the continuum fallacy suggests that there is no real difference between the points along the continuum (because all religions can be classified as cults, all religions are dangerous, manipulative, and harmful). The larger the continuum, the more fallacious the argument.

To avoid falling for this fallacy, recognize that very few things in life can be easily categorized. We classify things because it makes it easy for us to make decisions, but we often end up incorrectly seeing the world more discrete than abstract. Just because something is vague does not mean that it is invalid.

Examples:

“I’m not bald. See, I have a hair right here! As long as I have one hair, I will never be bald!”

“Do you like my beard? I know, it’s only a couple of hairs, but that technically means I have a beard!”

If you have a single straw, it is not a heap. The addition of another straw does not make it a heap. So because there is no clear delineation as to what quantifies a “heap,” there will never be such thing as a “heap.”

Because white is just a shade of light grey and because black is just a shade of dark grey, everything is then just a shade of grey and should be considered equal.

Why does the law state that you have to be 21 years old to drink? Does it really make any difference if you are 20 years and 364 days old? That is absurd. Therefore if a single day makes no difference, then a collection of 1095 single days won’t make any difference, therefore, changing the drinking age to 18 will not make any difference.

Example a room is never either “hot” or “cold”, because of the continuum of temperatures. The fallacy causes one to erroneously reject a vague claim simply because it is not as precise as one would like it to be.

“If you can curve the test to a 69, why not curve it to a 70?”

A salesman telling you that an extra $20 on your credit card won’t make much difference.

“One coke won’t re-addict you to caffeine.”

“What constitutes a ‘disabled’ person?”

“If you can’t draw a line between liberals and socialists, then there is no difference.”

“Smoking one cigarette won’t harm my health. And two cigarettes is only one more than one. So the second cigarette won’t hurt me. And three cigarettes is only one more than two. So that third cigarette won’t hurt me either. Where do you draw the line? You can’t. So I can smoke as many cigarettes as I want and it won’t ever hurt me.”

“Living cannot be distinguished from not living because the placement of a definitional line cannot be drawn between the two, so murder is non-existent.”

“Everyone is skeptical about some things; therefore everybody/nobody can be labelled a skeptic.”

“There’s no real difference between socialism and communism.”