Tag Archive | Logical Fallacy

Project Logicality | The Non Sequitur Fallacy


What’s going on when the reasons we give to support or refute a statement have no relation to it at all? What is the fundamental error of reasoning underpinning almost all logical fallacies, and when does this represent special cases?

Here we discuss the general fallacy of the Non Sequitur, Latin for does not follow.

This can generally refer to any sort of logical fallacy, any argument where a logical connection between premises is implied that just isn’t there.

This fallacy is often found with other forms of invalid reasoning in the very same statement. Here’s a couple of handy examples of the most common form:

Our cult shall be feared by all, for Azathoth is freakin’ scary when annoyed.

Human-caused global warming is impossible, because it’s cyclical, the ozone hole over the antarctic is closing, cow farts, and Mars is warming too, not just the earth.

But there are more specific named forms of this fallacy as well:

The Fallacy of the Undistributed Middle:

In which a conclusion is incorrectly drawn from two given or assumed premises, and takes the form of:

All Xs are Cs.

A is a C.

So, A is an X.

An obviously ridiculous example would be:

All birds generate their own body heat.

My cats generate their own body heat.

My cats are birds.

There is…

…Denying the Antecedent:

Which takes the form of:

If C is true, then D is true.

C is false.

So, D is also false.

A good example would be:

If I am in ancient Athens, I’m in Greece.

I’m not in ancient Athens.

So, I’m not in Greece.

This is absurd, as there are many locations and times in Greece other than Athens or the Ancient period. There is also…

…Affirming the Consequent:

which takes the form:

If C is true then D is true.

D is true.

So C is true.

An example:

If my Senior Technician intends to transfer me to another project, she’ll have a talk with the Program Director.

My Senior Technician is going to talk with the Program Director.

She wants to get me transferred to another project.

This last is clearly an example of invalid reasoning because the Senior Tech could be seeing the Program Director for entirely different reasons than those given.

One problem people sometimes have with this fallacy is that it can be subtle, and they are often too proud to speak out when they cannot see how an argument follows, or are too polite to point out its lack of relevance to the speaker.

It’s important to more specifically pick out what is being said even as a less general sort of fallacy, including the non sequitur’s aforementioned variants.

So be careful that what facts you bring to an argument are actually relevant to the point you’re trying to make. Otherwise, it may just fail the application of the “so what” test!

Tf. Tk. Tts.

(Fully Updated, Retitled, Broken Links Removed on 2017.06.06)

Project Logicality | The Argument from Ignorance


Screen Shot 2016-04-07 at 21.28.48One of the first things to discover when adopting a skeptical viewpoint is how vastly ignorant we all are of much of what there is to know. But ignorance isn’t bliss, it’s oblivion. And it’s evil twin, the illusion of knowledge, is downright dangerous.

Here we deal with a common mistake in thinking that exploits ignorance, trying to make it seem like knowledge, the Argument from Ignorance, also the Appeal to Ignorance or in Latin, ad ignorantiam.
Using this argument does not imply that one is ignorant in any demeaning sense, merely that the one using it isn’t making a valid argument or a reliable claim.

It attempts to make a definite claim to understanding by using what is not known rather than what is. It often takes the general form of:

I don’t know X, so I know Y.

Or put differently it goes something like this:

No one has proven X false (or true), so X must be true (or false).

Or perhaps:

I can’t explain X, so I can explain X.

A few examples follow:

No one has proven that Godzilla doesn’t exist, so Godzilla is real.

 

I’ve never seen any real, absolute, rock-solid proof that the Apollo astronauts landed on the Moon, so the Apollo missions were a hoax.

There’s no fallacy committed when there’s knowledge of missing evidence that should likely be found, and it’s known what the expected evidence should be. Absence of evidence in the right context is indeed evidence of absence when its lack is glaringly obvious, even if it’s not absolute proof of absence!

There’s no fallacy committed in and of itself when acting upon incomplete data for precautionary purposes, such as the threat of terrorists, who can be expected to operate in secret until they strike, if and when they do, or acting upon the threat of global warming in the absence of total certainty.

The following is a valid argument:

All of the scheduled openings of this library are listed. I don’t see a listing of it opening at this hour of the day. So it must be that the library is closed until two hours from now.

This, however, is not:

I see a strange light in the sky. I can’t think of an explanation for it off the top of my head, so it must be the aliens from Independence Day!

Or this:

There are gaps in the fossil record. I do not know of a plausible explanation as to why there are such gaps. So it must be that a Intelligent Designer has created or interceded in the creation of life.

A variation of this is Confusing the Unexplained with the Unexplainable, which is fallacious because it assumes implicitly that the current state of knowledge represents the ultimate limits of the knowable, which is just wrong on so many levels.

There’s a possibly apocryphal anecdote floating about of a patent clerk in the late 19th or early 20th century who quit his job, because he thought that everything important had already been invented.

There’s also the silly claim, still circulated, that it’s impossible for bumblebees to fly because science can’t explain it, therefore it’s magic. Well, science has explained it, and it deals with the mechanics of a bumblebee’s wings and the physics of fluid dynamics.

This is understandable, even from perfectly normal, intelligent, sane, and sincere people. It’s reasoning from psychologically available information rather than an examination of more complex and difficult data that may not come as quickly or easily to mind.

It just so happens that supernatural or paranormal explanations are among the easiest to conceive of on the spur of the moment. They are more immediately available, and we are more prone to them through the biases and mental shortcuts we take in our default thinking under whatever narrative influences our brains at any given moment, to paraphrase Dr. Steven Novella.

In informal argumentation the fallacious use of the argument from ignorance is not a violation of logical form as much as an attempt to subvert efforts toward getting at sound explanations for our claims.

It’s important not to confuse a lack of evidence for its presence, though absence of evidence can indeed be evidence for absence in the case of demonstrating the existence of entities in the real world. If the data you logically expect to see as a consequence of a phenomenon just isn’t where is should be found, that’s a good sign that it’s not real.

The prudent position, the conservative one, is to abstain from postulating unobserved and unobservable things, or those which can and should be observed but tellingly are not.

Otherwise, belief in such entities comes down to a matter of faith, and that is entirely one’s own choice to make.

Tf. Tk. Tts.

(Last Update 2017.06.06)

Project Logicality | Arguing by Assumption – The Enthymeme


Many arguments we make in daily life are incompletely stated, and less than completely certain in both structured debates and in informal discussions.

Some such arguments are called Enthymemes, arguments in which one of the premises, or the conclusion, is not stated but implied and needed for the argument to follow.

Why leave these out?

It depends on the situation, and the shared understanding of those involved in the discussion.

Generally, one part of an argument may be unspoken because it’s assumed by both and doesn’t need to be stated. So these parts will need to be teased out by a third-party analyst of the argument to determine fully what is being argued.

This can be an intellectually honest form of argument, and I offer some examples here.

I’m using here standard form deductive syllogisms—conditionally certain three-part arguments with two premises and a conclusion—for ease of presentation. The first is a 1st order, or unstated major premise argument.

The Magna is a mutant.
So the Magna is radioactive.

With the major premise being:

All mutants are radioactive.

This one has a hidden minor premise, or 2nd order enthymeme structure.

Not giving the proper homage to the Nine Who are One will endanger all our lives.
So we should not fail to give proper homage to the Nine.

With the hidden premise given as:

The Nine would wish us to do that which preserves our lives.

Finally, we have one in which the conclusion is left unstated, of the 3rd order:

We must deal ruthlessly with all freakishly powerful threats.
The Mirus is a freakishly powerful threat.

It’s not hard to see where this one will go… The conclusion, though unstated, should be obvious.

In some situations this sort of argument is less than intellectually honest, when the assumptions are NOT shared, or need to be fully expressed, this may be used to obscure matters as a rhetorical fallacy, as a tactic that hides the meaning of an argument and makes misdirection and confusion easy.

This happens when the aim intended, or not avoided, is thwarting honest critical discussion. I’ll provide an example of this as a fallacy, this one from a hypothetical creationism/evolution debate in which the major premise is obscured:

No fossil meeting my (impossible to satisfy) criterion as a transitional form has ever been found,
So there are no transitional fossils, so evolution is false.

But here is the missing major premise, NOT shared or expressed, and assumed only by the creationist:

To count as transitional, a fossil must be an impossible, half-formed monstrosity combining unlikely features of dissimilar species or ‘kinds,’ like a lizard/bird hybrid with incomplete, useless wings… (or the supposedly impossible ‘crocoduck,’ AKA, dinosaur genus Spinosaurus)

‘Enthymeme’ has also been used to refer to probabilistic arguments, such as those used in inductive logic or in much informal logic with language inextricably bound up with an argument’s content, with the conclusion following from the premises more or less strongly depending on the audience.

One such claim may be “Present-day Continental philosophy is not credible,” which could elicit different responses and have differing levels of credibility depending on the chosen philosophical schools of those hearing or reading it.

As can be seen, some of the very same sort of statements used in ordinary argumentation can be fallacies, and indeed, when informal, their fallacious nature depends on their misuse as argument strategies, not so much the the structure of the argument but more often violations of procedure.

Many informal fallacies are not always such, but even otherwise effective arguments, when they are put to specious use, are pure argumentative poison no matter their rational structure.

Tf. Tk. Tts.

(Updated, Links Removed, Image Added on 2017.06.06)

Project Logicality | Reducing to Absurdity


What happens when we carry a train of reasoning to its ultimate extreme, far past the reaches of sanity to the realm of the patently absurd? Here, we discuss such an argument in informal logic, borrowed from formal mathematical reasoning, and here known as the Reductio ad Absurdum.

In formal logic it may be used to show an argument’s claim to be false by following it to its ultimate logical conclusion, revealing a contradiction, an absurdity, or it may be used as a form of Straw-Man argument, known here as the False Reductio. I’ll deal first with the latter.

This works by forcing a conclusion that while absurd, doesn’t use the actual reasoning of the original argument, such as:

If you’re skeptical of the existence of UFOs, Bigfoot, and ancient aliens, then you must also be skeptical of the existence of the Taj Mahal, the Sydney Opera House, and the Empire State Building, since you’ve never been there to see those places.

This is fallacious because the proportional nature of the claims requires proportional standards of evidence. The criteria for each differ, and the argument itself ignores the use of evidence other than anecdotal testimony and grainy, low-resolution, or obviously photoshopped videos and photos.

Here is one of my favorites:

If you don’t believe in psychic abilities then you also disbelieve in dark matter and dark energy, so 90% of the Universe does not exist to you because you haven’t seen those either.

Again with ignoring evidence other than personally witnessing something. Also, it fails to consider the fact that though there is some question as to what dark matter and dark energy are, they have been reliably observed by their effects on the visible universe itself, and the evidence shows that they are real. Clearly, elusive supernormal psychic abilities and invisible but indirectly observable astrophysical phenomena are not analogous.

But all is not without a ray of light in the dark. There is an informally valid and intellectually honest use of this as well, to highlight the fallaciousness of some extraordinary claims. Here, the actual train of logic of the original argument is kept intact.

Here are a couple of silly claims I’ve come across:

The ancient Egyptians could not have built the pyramids without alien or Atlantean help. They were far too primitive a civilization.

 

In order to know what a human skeleton looks like, the Maya and Aztecs must have been given X-ray machines by ancient astronauts.

Such claims reek not only of thinly disguised racism and colonialist arrogance, but stupidity and historical shortsightedness as well. Typical of most of the claims of pseudo-archaeology, especially where ancient non-whites are not given due credit for their accomplishments.

And skeletons? Come on, that’s just silly!

Meh!

Here, we may apply the same train of logic to what the proponents of these ideas, mostly whites of Western descent, dare not apply it to: historical Europeans:

How could the Medievals possibly have had the intelligence to invent such marvels as the crossbow, stained glass windows, steel armor and weapons, and those massive cathedrals! They had to get their technology from aliens, because they were too inept to come up with them on their own! They must have gotten medical imaging technology from the aliens too, because Medieval art has lots of skeletons in it, and how could they have possibly known what those looked like without using it?

Absurd? Clearly it is, and in retaining as closely as can be the reasoning of the original applied to another subject, it shows that.

A side note: Technology is cumulative, and evolves over time, with earlier, precursor technologies leading to better, more advanced ones, with archaeological remnants to show this progression, no matter the location, or ethnic and cultural makeup of the civilization. This is true even dating as far back as the Paleolithic with stone tools.

Never underestimate human genius. There exists brilliance in every human era, with no need to gift early peoples with technology from super-civilizations for such tasks as constructing even impressive monuments, which require only engineering, tools, and social organization which we know they had, as opposed to the claims of pseudo-historians in massive, and dare I say, monumental, arguments from ignorance.

But I digress.

Reason is a tool. Use it well and it will serve you reliably, leading to the acquisition of more true conclusions than false ones. But abuse it, and the content of the claims you accept and promote becomes much more prone to error. Especially when you misrepresent the chain of another’s reasoning for ideological ends.

Tf. Tk. Tts.

(Last Update: 2017.06.06)

Project Logicality | Reducing to Absurdity


What happens when we carry a train of reasoning to its ultimate extreme, far past the reaches of sanity to the realm of the patently absurd? Here, we discuss such an argument in informal logic, borrowed from formal mathematical reasoning, and here known as the Reductio ad Absurdum.

In formal logic it may be used to show an argument’s claim to be false by following it to its ultimate logical conclusion, revealing a contradiction, an absurdity, or it may be used as a form of Straw-Man argument, known here as the False Reductio. I’ll deal first with the latter.

This works by forcing a conclusion that while absurd, doesn’t use the actual reasoning of the original argument, such as:

If you’re skeptical of the existence of UFOs, Bigfoot, and ancient aliens, then you must also be skeptical of the existence of the Taj Mahal, the Sydney Opera House, and the Empire State Building, since you’ve never been there to see those places.

This is fallacious because the proportional nature of the claims requires proportional standards of evidence. The criteria for each differ, and the argument itself ignores the use of evidence other than anecdotal testimony and grainy, low-resolution, or obviously photoshopped videos and photos.

Here is one of my favorites:

If you don’t believe in psychic abilities then you also disbelieve in dark matter and dark energy, so 90% of the Universe does not exist to you because you haven’t seen those either.

Again with ignoring evidence other than personally witnessing something. Also, it fails to consider the fact that though there is some question as to what dark matter and dark energy are, they have been reliably observed by their effects on the visible universe itself, and the evidence shows that they are real. Clearly, elusive supernormal psychic abilities and invisible but indirectly observable astrophysical phenomena are not analogous.

But all is not without a ray of light in the dark. There is an informally valid and intellectually honest use of this as well, to highlight the fallaciousness of some extraordinary claims. Here, the actual train of logic of the original argument is kept intact.

Here are a couple of silly claims I’ve come across:

The ancient Egyptians could not have built the pyramids without alien or Atlantean help. They were far too primitive a civilization.

 

In order to know what a human skeleton looks like, the Maya and Aztecs must have been given X-ray machines by ancient astronauts.

Such claims reek not only of thinly disguised racism and colonialist arrogance, but stupidity and historical shortsightedness as well. Typical of most of the claims of pseudo-archaeology, especially where ancient non-whites are not given due credit for their accomplishments.

And skeletons? Come on, that’s just silly!

Meh!

Here, we may apply the same train of logic to what the proponents of these ideas, mostly whites of Western descent, dare not apply it to: historical Europeans:

How could the Medievals possibly have had the intelligence to invent such marvels as the crossbow, stained glass windows, steel armor and weapons, and those massive cathedrals! They had to get their technology from aliens, because they were too inept to come up with them on their own! They must have gotten medical imaging technology from the aliens too, because Medieval art has lots of skeletons in it, and how could they have possibly known what those looked like without using it?

Absurd? Clearly it is, and in retaining as closely as can be the reasoning of the original applied to another subject, it shows that.

A side note: Technology is cumulative, and evolves over time, with earlier, precursor technologies leading to better, more advanced ones, with archaeological remnants to show this progression, no matter the location, or ethnic and cultural makeup of the civilization. This is true even dating as far back as the Paleolithic with stone tools.

Never underestimate human genius. There exists brilliance in every human era, with no need to gift early peoples with technology from super-civilizations for such tasks as constructing even impressive monuments, which require only engineering, tools, and social organization which we know they had, as opposed to the claims of pseudo-historians in massive, and dare I say, monumental, arguments from ignorance.

But I digress.

Reason is a tool. Use it well and it will serve you reliably, leading to the acquisition of more true conclusions than false ones. But abuse it, and the content of the claims you accept and promote becomes much more prone to error. Especially when you misrepresent the chain of another’s reasoning for ideological ends.

Tf. Tk. Tts.

(Last Update: 2017.06.06)

Project Logicality | Moving Goalposts


Have you ever had a discussion with someone who never lets you convince them on some matter no matter the strength of the evidence? What’s going on when people, even perfectly sane, otherwise rational, and sincere people give excuse after excuse as to why the evidence and argument just isn’t ‘good enough’ to compel their assent no matter its truth or validity?

Note that it is easily possible to set the bar for evidence too low, but we can also make it impossible, or virtually so, to reach.

So here, I deal with a favored rhetorical tactic of cranks, pseudoscientists, grand conspiracy theorists, charlatans of all stripes, and yes, ordinary people in everyday discussion: the Moving Goalpost.

Most people are fairly closed-minded and find changing their stance on things uncomfortable. It takes good metacognitive skills, thinking about thinking, to correct this tendency.

The fallacy takes its name from an analogy with American football, in which the goalposts are always out of reach of whoever is carrying the ball, and continue to recede further still.

With this tactic, the more unreasonable the standard of proof for refuting or confirming the claim, the better. It involves either arbitrarily redefining one’s claims to put them conveniently out of reach of any disproof, or setting impossible standards from the very beginning.

The objective here is to avoid having to rescind whatever claims one is making, when one has a political, financial, personal, or ideological stake in a position. For some, no amount of evidence and reason is enough, and it shows in this use of rhetoric.

A couple of examples might be:

Show me just one experiment conducted in a lab on Earth that has ever created dark matter, directly measured gravity, manufactured a black hole, or generated controlled stellar fusion! Establishment Cosmology™ is silly, fallacious, and wrong!

This argument clearly sets impossible standards from the beginning.

It and what follows use a version of the “show me just one proof” gambit common among creationists and crank cosmology proponents (Sometimes those are one and the same!).

The next illustrates shifting standards of proof each time evidence is presented:

I want to see any example of a transitional species before I think evolution even remotely plausible! Just one!

Tiktaalik? Ambulocetus?

There are still gaps in the fossil record between those and what came before and after! Where’s the evidence for those??

You’ve filled in those gaps?

Now there are more gaps to fill! Fraud! Fake! Amoral evilutionist! Evolution is a sham!

It’s important to proportion to the claim just what criteria of evidence and logic you will accept, and to stick with that as your gold standard throughout. Set reasonable standards, then admit it and change your mind once those standards have been met.

Consistency might be called the bugaboo of small minds, but it’s what’s needed when assessing claims open-mindedly and rationally.

Tf. Tk. Tts.

(Last Update: 2017.06.06)

Project Logicality | The Argument from Final Consequences


What happens when we confuse cause and effect? What mistakes do we make in thinking backwards from effects to causes, based on little more than our preference or distaste for the perceived outcome or desired conclusion?

Here, we discuss the Argument from Final Consequences, a form of emotional appeal. It’s a form of argument from intent, from a perceived goal, or outcome. Here, the central claim of the argument is based entirely on the desirability of that outcome, effect or purpose of that central claim.

This is fallacious when making factual statements, for it assumes that the desirability of the outcome makes the statement true, or lack of appeal makes it false, when the truth of a claim has little at all to do with the effects it has or how much we may like or dislike them.

Typically, arguments of this sort are inherently subjective in view, as they classify outcomes by personal value judgments—as wanted or unwanted—not on any prior fact, reason, evidence or other form of good grounding.

This fallacy differs from other appeals to emotion in that it makes a claim to a statement’s degree of truth depend on whether it is right or wrong, good or bad, pleasant or unpleasant. There are, of course, variations, including those on the following list, which is necessarily incomplete:

Appeal to Fear, such as the case of clergymen who demand that their congregations keep the faith or be damned.

Appeal to Ridicule, shading into the variant of an argument from incredulity. This could be a situation where one is told to accept what is claimed or be mocked or the claim itself is mocked.

Appeal to Flattery, as when a psychic tells her mark that she senses ‘psychic potential’ in her in order to further gain her confidence, as with any con game.

Appeal to Force, in the case of being told to accept something as true (or false) or face the threat of physical or legal consequences.

Appeal to Conspiracy, in which the truth of a conspiracy is claimed because the of alleged consequences of the truth being discovered by anyone not part the alleged conspiracy.

Appeal to Pride, as with claims that something is true (or false) because accepting it entails the consequences on one’s honor, reputation, or otherwise results in gaining or losing face.

Appeal to Motive, in which something is claimed to be so because the ones alleged to be responsible for it have or had something to gain from it.

Appeal to Hatred, in which something is claimed to be true because those it relates to are objects of hatred and bigotry.

Appeal to Pity, in which something is claimed to be false (or true) based on an appeal to one’s compassion or generosity toward the subject of the claim.

Appeal to Envy, in which something is claimed to be so, or not, because it involves something coveted.

Wishful Thinking, in which something is said to be true (or false) merely because one magically wishes it so.

Below is the general form of the argument:

If X, then Y will happen.

Y is desired (or undesirable).

So X is true (or false).

A few examples follow:

Humans will create an intergalactic empire because we need to have one in order to prosper.

Cthulhu must exist, or there would be no one to devour the world when the stars are right once again.

For evolution to be true, humans would have to be mere amoral beasts, meat robots without guidance or purpose, so evolution must be false.

There are a couple of subtly similar sorts of argument which are nonetheless valid:

  1. When claims of factual truth are not involved in the argument made, such as arguments of policy or involving actions to undertake.
  2. In the arguments involved with certain philosophical moral theories, such as Consequentialist Ethics, and when one is not implying that a consequence (Y) is undesirable but that it is merely false:

If X is true then Y is true.

Y is evidently not true.

So X is false.

That last example is valid according to the form of Modus Tollens, or mode which denies, the negative form of the conditional argument Modus Ponens. 

This can be a subtle error in reasoning to pick out and identify, but once figured out, is pretty apparent. Most of all, be careful of such fallacies in your own argumentation, for its subtlety can making it easy to commit without notice at first.

Tf. Tk. Tts.

(Last Update: 2017/06/06)