Logical fallacies

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Jared Alesi's picture
Logical fallacies

Here is a list of logical fallacies. It's not comprehensive, but it's a start. Try to avoid using these.

Non Sequitur: when a conclusion does not follow from its premises.
Begging the question (circular reasoning): when a conclusion is assumed within the premises.
False Dichotomy: when a choice is erroneously limited to two options when more are possible.
Slippery slope: when the triggering of one event is assumed to trigger more without probable cause.
Ad hoc: an unprovable claim.
Argument from ignorance: the assumption that the interlocutor's ignorance of data is proof of an alternative.
Appeal to tradition: the assumption that things should remain the same because they worked in the past.
Argument from person experience: the act of relaying memories as fact, despite their unreliable nature.
Argument from absurdity: taking a conclusion or premise to unconventional territory in debate to make it seem absurd.
Fallacy fallacy: the assumption that one logical fallacy in a syllogism disproves the entire thing.
Personal incredulity fallacy: the assumption that since the interlocutor cannot understand it, it must not be true.
No true Scotsman: changing the definition of a term to exclude given evidence against a claim.
Equivocation fallacy: using different definitions of a word throughout a syllogism to support the conclusion.

Most these terms have Latin names, but I don't know them all off the top of my head. I suspect Sheldon does. As an added bonus, a syllogism is the expanded parts of an argument, which shows the premises in their simplest forms.

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Sheldon's picture
In religious apologetics I've

In religious apologetics I've seen them all used, but by far and away the most commonly used is argumentum ad ignorantiam. What Professor Dawkins coined the God of the gaps argument.

TheBlindWatchmaker's picture
Argument from authority and

Argument from authority and straw-man are all too common.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
I think you would enjoy

I think you would enjoy studying psychology. It can give you a unique perspective of fallacies, because you're not only studying the machine that produces them and can correct them, you study why it produces them in the first place.

For example, during early childhood the biggest obstacle to logic is focusing on one aspect of a thing, to the exclusion of all others. Children might focus on certain aspects of apperances and not see beyond that. A girl with short hair, is by all definitions, a boy. These children also view the world as unchanging, and make errors accordingly. As a consequence they may also view the world as irreversible.

I think the most famous fallacy in children deals with conservation. When the same amount of water in a large cup is put into a skinny cup, they'll think there is more water than before, based on its appearance. As they grow up they'll overcome these tendencies, and acquire new abilities, such being able to use categories.

During adolescence you encounter egocentrism. Teens may see their thoughts and feelings as unique, and worse than what others experience. They may also view themselves as invincible. However, more importantly, adolescents start thinking abstractly. They can think of possibilities and hypotheses. They become able of deductive reasoning and much more. However, some of the logical fallacies that adolescents still encounter include the sunk cost fallacy, and base rate neglect.

The story of cognition and logic continues developing throughout the lifespan. I would say that the cause of most lapses in logic in adulthood, are the result of Kahneman and Tversky's proposed two systems of information processing. In any given subject, particularly those we have some familiarity with, we first think fast and automatically. Yet we still retain the ability to think slower and more logically. The question that the brain (person) seeks to understand, is knowing when to use which system.

Jared Alesi's picture
I don't care for psychology.

I don't care for psychology. I like rigid facts supported by evidence and the analysis of real, tangible things. Psychology doesn't have that. Psychology is a sort of pseudo science, seeking to confirm beliefs by interpreting data to fit a narrative. Actual science depends on disproving itself to make progress, and progress it makes. In 1903, the first motorized flight was a shorter length than the wingspan of a Boeing 747. A short 66 years later, humans had walked on the moon. Meanwhile in psychology, we've no idea if anything Freud or Jung proposed is really true. Pretty much the biggest breakthrough in psychology that's supported by experimentation is conditioning, and we can't really test those things on people very easily without running into ethics barriers. But we don't have recorded evidence to suggest the existence of the id, ego, superego, unconscious, collective unconscious, or really any of those abstract ideas of psychology. And we'll likely never have a solid answer because we can't test for those things.

I like real science because it builds by destruction. You must disprove everything, and when you can't, it must be because it's true. People work to disprove our modern understanding of evolution and of quantum mechanics every day. We accept nothing as true until it's been rigorously tested. It's a bit like the foundation upon stone versus sand analogy. Science is built upon the stone.

My particular interest is in the field of engineering. It's not enough to know things, I want to use the knowledge too. I want to build and plan, optimize things, make stuff better. Clean energy, efficient machinery, better living, all of that. I want to do that.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
To be honest, I used to think

To be honest, I used to think like you. In fact, I started out as a biomedical student looking to get into neuroscience or neurology because I considered them to be "scientifically superior" to psychology. However, the more courses I took, the more I realized its not that they were "actual sciences" with "rigid facts," its that they were easy sciences. The questions they ask, and the answers they produce, are straightforward. I still love neuroscience, and any good psychologist worth his salt knows neuroscience. Its intellectually satisfying learning all the technical jargon of each part of the brain, such as the infundibulum or the substanstia nigra. Even saying the word neurotransmitter just sounds smart, and keep in mind I've been taught everything from how they are chemically sythesized, to what occurs when they interact with a receptor. But neuroscience is blind to the whole purpose of all these chemicals.

Psychology and neuroscience are two sides of the same coin, but psychology is far superior. The reason why should be inherently obvious: Chemistry and physics are the basic sciences, they are the foundation upon which everything else is built. A step above them you have biology, which is more complicated, more specific. Above simple biology you have the emergence of brains, arguably the most complex organ known to man. And emerging out of the biology of the brain, you have the human mind. Psychology is literally the epitome of the sciences, and arguably the hardest thing to study.

All a chemist has to study is chemisty, that is their world and they hardly ever move beyond that. But as a psychologist, I need to learn everything. For example, I need to learn about the physics of light, their wavelengths, their properties, their interactions with other objects. I then need to learn about the chemical reactions that occur within the retina as a result of a photon stricking it, which means I need a foundation in organic chemistry. I then need to learn the anatomy and physiology of the brain, and the path neurons take as they carry that information from the retina to the cortex. I then need to understand what a person is perceiving, not just what they are sensing. I need to understand how the mind interprets that visual information, because the color of the dress might be "blue and black," but the person might be seeing it as "white and gold." I then need to understand the behavioral responses of vision. If you're looking at a bear, will a person fight, flee, or freeze? I then need to understand statistics, probabilities and the theory behind them. Because what if a person doesn't run away? Suppose that 95% of the world runs away, but only 5% doesn't. Does that mean they have something wrong, is it a disease that inhibits fear, is it a gene, a birth defect? Well then I would have to know about culture and history and the social environment of a person. Because perhaps in their culture bears are viewed as gods, and therefore it is quiet reasonable for them not to be afraid. I not only need to know the foundations upon which a mind is built, but the context in which it exists.

Science is observation; and by now you know who studies how scientists make observations and make interpretations, who studies the limitations of memory, and the development of logical thinking which makes science possible (see attachment).


Attach Image/Video?: 

Jared Alesi's picture
That is where we differ. I

That is where we differ. I don't view psychology as the pinnacle but the nadyr because it doesn't do anything on its own. It's just a reiteration of other discoveries made by real sciences like neuroscience and biology. I would view chemistry and physics as the pinnacle because they are the most reliable and universal. Our understanding of biology is dependent upon chemistry. Our understanding of aerodynamics and ballistics depends on physics. In this way, psychology cannot stand on its own. We could literally never make sound progress in psychology without the other sciences. You could conjecture all day, but you need hard evidence to make any headway, and for that you need science. Psychology isn't scientific, it's science's little brother that needs help when it can't figure out a puzzle.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
"It doesn't do anything on

"It doesn't do anything on its own. It's just a reiteration of other discoveries made by real sciences like neuroscience and biology."

Well, its fairly common for people to think that, but those that do often don't know neuroscience. Take for example fear. We know fear exists: we can see it in others, we can experience it ourselves. But, how does knowing where fear is regulated in the brain help us understand fear? It doesn't. Unless you believe in souls, fear obviously exists somewhere in the brain, but its exact location is arguably unimportant. Fear is still fear whether it is regulated by the amygdala, or the hippocampus, or the superior olivary nucleus. A neuroscientist can't study fear and aggression without stepping into the word of psychology, but a psychologist can without stepping into the world of neuroscience.

I'll give you another example. Suppose you're in an accident, and sustained a head injury. The neurologist puts you in an MRI machine and doesn't find any lesions or contusion. You go back to school, but start noticing strange things. You're more forgetful than before, your grades also start declining, and you start having headaches. You go back to your neurologist but he still can't find anything wrong. Why? Because the tools of a neurologist are still very limited. They can't detect microscopic lesions for example. So he'll refer you over to a psychologist, because a good psychologist is better than an MRI machine. You simply cannot know whether a certain function has been lost by looking at pretty MRI pictures. You have to test it, and a psychologist knows how to test your behavior and cognition, your personality and intellect to determine what went wrong exactly. He'll be able to see how badly your memory was affected; or if he runs extensive behavioral tests, he'll be able to deduce what part of your brain was injured.

"I would view chemistry and physics as the pinnacle because they are the most reliable and universal."

That is what I mean by chemistry and physics being easy sciences, whereas psychology is a hard science. By reliable and universal, you seem to want the answer of 2 plus 2 to equal 4 consistently at all times and in all places. Chemistry more or less functions like that. What you don't seem to want, however, is for the answer to 2 plus 2 to change on you as a child develops; you don't want the answer to change depending on what culture the person was born; you don't want the answer to change based on what the person ate this morning, or what drugs they've taken.

The mistake you make, I think, is thinking that because studying the mind isn't easy, it is somehow less scientific.

Jared Alesi's picture
"Unless you believe in souls,

"Unless you believe in souls, fear obviously exists somewhere in the brain,"

No, there is no unless. Your own personal belief does not influence fact. You can believe all you wish that a purple troll farted the biosphere and all species of animals into existence, but that doesn't mean it is what is true. There is only one truth, and wishful thinking is not the way to find it.

As for your last statement, you completely misunderstand me. I don't think of psychology as unscientific because it is hard. I view it as unscientific because it does not use the scientific method. Even if you can't understand fear without psychology, that doesn't make it science. You're still working with an unverifiable claim. You do understand the problem with that, right? Perception is subjective, and a study of subjectivity has very little to do with objectivity. We may have an outline of 'propter hoc' that seems to work on a common basis with most people, but I assert that any other explanation could be considered just as valid because we don't have any evidence to support either alternative.

For example: Let's say that X person does Y action because of Z cause. We've observed the action, but since Z cause is entirely inside X person's head, we have no idea if Z cause is actually what we think it is. We could use process of elimination among similar cases to narrow down the possibilities of what Z is, but there's still a whole brain full of possible explanations that we can't rule out because there's still so much of the brain that is not understood.

Jared Alesi's picture
To further elaborate on fear,

To further elaborate on fear, consider that there are still competing hypotheses on the origin of fear, all of which share about the same level of credence.

Firstly, we have the idea that fear comes from experience. We fear large predators because we have seen what large predators do to their prey. Makes sense, but we don't know if this is the most accurate answer.

Then we have the idea that fear comes from instinct. We fear large predators because we have innate intuitions about large predators. This seems to be the case with most prey animals, but whether or not it is true with humans is harder to say, since humans are so far removed from predators at birth and through childhood that it's hard to have a true test.

Then we have the idea that both are partly true for some cases with some people. Or the idea that fear is dependent on external chemicals like foods.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
Ok, so I'm sure you know

Ok, so I'm sure you know music makes us feel good. Music can also instinctively make us afraid. They say that at the movies, if you wish not to be afraid, cover your ears and not your eyes. So sound can do a lot of things when it comes to emotions. Nobody has to learn that scary music is scary, to the contrary, we make scary music because it makes us afraid. Loud sudden sounds in particular do a number things. For one it triggers an attenuation reflex, so your inner ear attempts to block out the sound. Secondly, it triggers a startle reflex, you're immediately fearful. They reason why tornado sirens and fire alarms work is because they automatically makes us alert and afraid, they instill a sense of panic. Same reason why WWII pilots equipped their planes with Stuka sirens. From babies all the way to adulthood, people become startled at loud noises.

Great, so that shows the instinctual nature of fear. But fear can also be learned. That's where the famous Baby Albert experiments come in. The baby plays with a rat, happy as can be, with no fear. In the second trial however, the experimenter uses the startle response, by playing a loud noise and then immediately exposing the baby to the rat. And then in trial three the experimenter presents the rat to the baby again without the loud noise, and lo and behold, the baby is afraid of the rat. It cries whenever it comes near to him. Fear has been learned.

When I said any good psychologist knows neuroscience, here's why. One famous theory of emotion states that what we call emotion, is nothing more than the summation of what our bodies are doing. So when you feel your heart rate rising, your blood vessels constrict, and your muscles quivering, that information makes you go oh, I'm afraid. Cool, so how do we test that? Easy, cut the nerves that take information about heart rate, blood pressure, and muscle position to the brain, and see what happens.

Does any of this sound unscientific?

Dave Matson's picture
Jared Alesi,

Jared Alesi,

I think you should draw a distinction between experimental psychology and the rest of it, a subset of the latter being the non-science of Freud and Jung. Freud has been thoroughly discredited as far as I can tell. I imagine that Jung would fall into that same category.

ʝօɦռ 6IX ɮʀɛɛʐʏ's picture
Its helpful to think of Freud

Its helpful to think of Freud as the alchemist to our chemistry. He was proto-scientific rather than pseudoscientific. Freud and Jung mostly have historical importance, particularly for the clinical side of psychology. Yet even with Freud you get a sense of how interdisciplinary psychology is, he was first and foremost a medical doctor and neurologist.

Jared Alesi's picture
Fair enough. I'm not sure

Fair enough. I'm not sure Freud has been discredited, however, because it seems hard for any evidence to support or oppose his hypotheses.

Dave Matson's picture
Freud has been discredited,

Freud has been discredited, if I am right, in the sense that he is no longer a paradigm for psychology. That is, experimental psychology has assumed the mantle of the science of psychology (clinical psychology having largely been rendered impotent) and in that arena Freud is mainly an historical footnote. Some of his observations were astute, but his interpretations were hardly subject to scientific controls and were, quite often, nonsensical. That's my take anyway.

Arcturus Alexander's picture
I applaud you and your


CyberLN's picture
Are you asking if the theory

Are you asking if the theory of evolution has been shown to be false?

Arcturus Alexander's picture
Pardon my editing in the

Pardon my editing in the first post, but yes, that is what I am asking. Has it been shown false. If so can you (someone) please explain how that happened?

CyberLN's picture
Has it been shown to be false

Has it been shown to be false by whom?

Arcturus Alexander's picture
Well, let me ask this

Well, let me ask this question instead of my past question. Has there been an argument disproving evolution? I am not sure who. I am just asking has it been disproven?

CyberLN's picture
There certainly have been

There certainly have been attempts to posit overall refutations. But none, to my knowledge, have been shown to hold water.

There may be legitimate arguments that challenge one or more details. That’s how science works.

Arcturus Alexander's picture
I applaud you and your

I applaud you and your interest in engineering. Might I recommend Nikola Tesla as a person to look into if you haven't already.
My reasoning for this comment though is because I've got a ligit question. Has the theory of evolution not already been laid low?

Sheldon's picture
"Has the theory of evolution

"Has the theory of evolution not already been laid low?"

Turn on any news channel, or log onto any major news network's website, if you're still unsure http://w2.vatican.va/content/vatican/en.html the Vatican seems to be unaware this has happened.

Also The Nobel committee, I checked and no one has been recognised for would be a massive advancement in scientific knowledge by showing a huge scientific theory was in fact false. I also tried the Templeton foundation's website, they also seem to have missed this.

However the real surprise is that the Creation Institute have missed that their goal has been achieved.

Then of course there is the entire scientific world who seem unaware they accept as fact something that has been falsified.

So no, evolution has not been "laid low" and is still a scientific fact, duh!

Arcturus Alexander's picture
What would you make of the

What would you make of the "cosmological argument"

Sheldon's picture
It's a first cause argument,

It's a first cause argument, so it doesn't even present an argument for theism or a deity. It is also woefully flawed.

1) everything that begins to exist has a cause

Flaws in premise 1:

a) We don't know it is true for start as we don't know everything
b) Where we do know that this is true it only applies in a temporal condition
c) in every instance the cause is material, not once as a supernatural cause been evidenced.

Premise 2 The universe "began" to exist

Flaws in premise 2

a) Since time didn't exist prior to the point of origin of the universe it didn't begin to exist in the same sense as the examples in premise 1, so we have no reason or evidence that the law of cause and effect apply to a non-temporal condition.

Conclusion of KC argument
The universe had a cause

Flaws in conclusion
a) The argument has not shown that the law of cause and effect applied to the origin of the universe which was a non-temporal event.
b) Since we have only one universe we cannot properly test this conclusion.
c) Even without the obvious flaws this argument is for a cause not for a deity.

Now for the assumption that William Lane Craig makes at the end of this argument

The cause of the universe is the christian deity.

We don't really need to bullet point logical flaws here, as he is making a pure assumption, with no evidence to support it and defining his deity in a way that he thinks makes it necessary in order to to believe in a created universe is of course begging the question, as he's assuming in his argument the very thing he is arguing for.

Lastly and going back to the inductive reasoning in premise 1, if he is going to create a rule that everything that begins to exist needs a cause, because all the examples we have evidence for have a cause, how can he then ignore the evidence of every single example having a natural physical cause? WLCraig then also ignores that this would mean his deity would need a cause by the same logic, but he then uses special pleading to claim his deity is an exception to the rule he has tried to create.

This argument is woeful, and modern physics also has models for the origins of the universe that fit all the available evidence, and none of them require a cause, let alone a supernatural cause. Lastly WLCraig's assumption that a deity created the universe has no explanatory powers whatsoever, it is a fallacious appeal to ignorance.

Arcturus Alexander's picture
The start of evolution in our

The start of evolution in our universe is thought to be the Big Bang theory. That an explosion somehow made something instead of destroying something, not that there was anything to destroy. Perhaps the BB wasn't the start, perhaps it was just a mile marker in the history of the universe. Regardless there would still need to a cause for everything that could of happened prior to that. Otherwise there would just need to be an infinite amount of causes which in theory us being here doesn't make sense. Granted I am not the first to use this argument, so I claim no sense of originality with this argument but this seems to be very compelling to me.

Sheldon's picture
THE big bang theory was not

THE big bang theory was not explosion, this is quite a popular misconception among religious apologists and creationists.

"Perhaps the BB wasn't the start,"

Assumption, what evidence can you demonstrate for this assertion?

"Regardless there would still need to a cause for everything that could of happened prior to that. "

That's a logically fallacious argument called begging the question, you have to demonstrate your claim with evidence not simply assert it. Also it's could have happened, not could of happened. Also since time and space would not have exited prior to the origin of our universe you are making assumptions about a condition we can't test.

"Otherwise there would just need to be an infinite amount of causes which in theory us being here doesn't make sense. "

That's an argument from ignorance fallacy, Not having an explanation means it's fallacious to then draw conclusions.

"Granted I am not the first to use this argument, so I claim no sense of originality with this argument but this seems to be very compelling to me."

Then you need to study it properly and not just regurgitate the views of religious apologists like William Lane Craig, as it is not remotely compelling, it is a collection of irrational and fallacious claims. There are also models based on the big bang theory that fit all the available data and none of them need a cause or rely on infinite regress. However the assumption that this unevidenced cause is a deity is special pleading as it assumes the deity is an exception to this rule it has assumed is necessary for a cause..

CyberLN's picture
JF, you wrote, “The start of

JF, you wrote, “The start of evolution in our universe is thought to be the Big Bang theory. ”

Nope. One has nothing to do with the other.

Are you learning your science from TV, specifically the song by the BNLs for the show “Big Bang Theory “?

Sushisnake's picture
I hope you're not dissing the

I hope you're not dissing the BNLs, Cyber. Don't make me come up there and sing it to you. Remember the scene in 'Ghost' where Sam kept singing 'I'm Henry the Eighth" to Whoopee Goldberg? It'll be like that.

CyberLN's picture
I enjoy them a great deal,

I enjoy them a great deal, Sushi! I am, however, convinced that many folks have gotten their notions of what evolution is from that song.

MCDennis's picture



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