No.

No. Logic is a systematic way of dealing with propositions and their truth value. You don't get to say a rule of logic is bad or a fallacy is good just because false beliefs might generate a positive outcome.

Think Zeno's pardox. Logically/mathematically one CANNOT travel any distance. However one can easily walk from one place to another. This is a perfect example that our world and this universe itself is not limited in any way by our logic and its rules. That leaves plenty of room for perfectly applicable fallacious thinking.

No.

A valid inductive inference can use rules that would be fallacious in pure deductive logic. The trick is knowing what to use and when.

No.

Paradoxes, like Zeno's, have potential answers.

The point is to resolve the paradox by rejecting the premises. Zeno's paradox is not really a paradox per say, but an argument meant to illustrate that changes we observe, such as motion, are illusions. Unless we can illustrate an error in Zeno's thinking in some way, it holds true.

If fallacious reasoning is a product of millions of years of evolution, then we should cherish it.

The errors with all syllogisms is always the propositions.

Hence, take my above proposition with a grain of salt.

If a lion is in the bushes then the leaves will rustle
The leaves are rustling
Therefore there's a lion — TheMadFool

This is a deductive fallacy, but it is a textbook case of retroductive (or abductive) reasoning. "There's a lion" is a hypothesis, a plausible explanation for the rustling leaves. We have reason to suspect that it is true (and behave accordingly), but no warrant for claiming to know that it is true.

Seeing one tiger attack and devour another deer should be logically sufficient to realize tigers kill deer. — TheMadFool

It is logically sufficient to conclude that some tigers kill deer. Since a deer cannot know in advance whether any particular tiger that it encounters happens to be one that kills deer, it has reason to suspect that all tigers kill deer (and behave accordingly), but no warrant for claiming to know that this is the case.

The bottom line is that deductive logic is about explicating our premisses - figuring out what else we know, based on what we know that we know - not determining what actions we should take accordingly; especially in scenarios like these, where it is obviously prudent to err on the safe side rather than find out the truth of the matter.

I think it's been clarified here that there is a distinction between inductive and deductive logic, with the former allowing for probabilistic conclusions and the latter allowing only for necessary conclusions. It's the distinction between what is likely and what is entailed.

Keeping the above in my mind let us now consider the theory of evolution whose basic message is we retain and pass to our progeny traits with survival advantage. If this is true am I wrong in inferring that our minds, its processes (including fallacious thinking) are life-critical traits we should be actually cultivating and reinforcing instead of avoiding and purging from or minds? — TheMadFool

Evolution developed the ability to think logically--at least sometimes, in instances where there was time to think.

"Logic" isn't a product of evolution; logic is the product of our ability to think and the capacity of our culture to develop certain kinds of thinking.

In any event, when it comes to lions, tigers, and bears in the bushes, deer and humans rely on flight or fight responses which have nothing to do with logic, or thinking either.

If you agree with all I've said until now don't you think we're making a mistake in so confidently blacklisting so-called fallacious reasoning? — TheMadFool

It depends on what you are after.
You can have a contented healthy life even if you go about it never knowing of logical fallacies or cognitive biases.
But when you are after a deeper understanding you will not make progress until you come to terms with these shortcomings.

I agree here.

Evolution got us to the stone age and we were content there for thousands of years.
Critical thinking is what has allowed us to go beyond that technological level.

Logic is concerned with validity.

An argument is valid when it is impossible for the premises to be true and/or the conclusion false.

The problem with fallacies is that they do not guarantee validity.

So yeah, it's wise for an animal to assume that there's a lion in the brush if the leaves are rustling in a particular way, but it's still a fallacy because that assumption does not guarantee validity. In other words, it's possible that it's not a lion in the brush after all. Therefore that's not a valid conclusion given the premises--because the premises are true, but the conclusion could be false, and validity only obtains when it is IMPOSSIBLE for the premises to be true and/or the conclusion false.

1. Fallacy of affirming the consequent.
The above is a fallacy in deductive logic. Consider the following argument:

If a lion is in the bushes then the leaves will rustle
The leaves are rustling
Therefore there's a lion

While the fallacy is apparent it appears very very reasonable to use this form of inference if you were a deer or any other prey animal. It could make the difference between life and death.

2. Fallacy of hasty generalization. This is also a fallacy but think yourself as a deer. Seeing one tiger attack and devour another deer should be logically sufficient to realize tigers kill deer. In such cases NOT committing the fallacy could prove fatal for the deer.

These are just a few cases where fallacious thinking is life-saving. There could be others. — TheMadFool

Conclusion: ban deer and other such prey from being taught logic. They must be kept dumb for the sake of their own survival.

In any event, when it comes to lions, tigers, and bears in the bushes, deer and humans rely on flight or fight responses which have nothing to do with logic, or thinking either. — Bitter Crank

No, no, no. They just didn't concentrate enough in logic class. Typical deers. The deers in my class were always slacking off. But it worked out well for them, because the clever ones ended up being devoured by lions.

As a novice myself I've read a handful of introductory books on logic. — TheMadFool

I don't think you've read these books that carefully myself. The very small one by Graham Priest all on its own will put you right, and that's despite the fact that he believes in wacky logics that few other people believe in.

Keeping the above in my mind let us now consider the theory of evolution whose basic message is we retain and pass to our progeny traits with survival advantage. If this is true am I wrong in inferring that our minds, its processes (including fallacious thinking) are life-critical traits we should be actually cultivating and reinforcing instead of avoiding and purging from or minds? — TheMadFool

When positions and arguments are framed properly, we call them sound and valid; not fallacious. A fallacy is by definition an argument whose conclusion we choose not to accept because it's conclusion is either not necessitated (deduction) or not made adequately likely (induction) by it's premises.

The bushes rustling for instance is decidedly NOT fallacious when one takes into account overall survival strategy and the general context in which such a decision would be taken. If lions are known to leap from rustling bushes, even in only 1/1000 instances of bush rustling (it's rare for it to actually be a lion), it will still be quite rational to presume it is a lion for safety reasons and flee none the less. Depending on the prevalence of lions, bush rustling, and the combination of the two, it might be entirely rational for a person to assume that every bush contains a lion and for survival purposes burn them all down. The (proper) conclusion is actually that there is a chance that there is a lion in the bush, and based on the adequacy of that chance, a decision is made to flee or not flee based on probability (lacking a better term). Here the fallacy is not the argument or the conclusion, it's the very acceptance of the conclusion (in deciding to flee) when it is actually not strategically productive to do so (pertaining to the goals of the individual in question).


p1.1 Meteorites could kill someone if struck by one
p1.2 Meteorites hit the earth every day
p1.3 You are on the earth

c1.1 [p2.1] You might get hit by a meteorite

c2.1 DUCK!

The first argument is sound and valid, it's precisely c2.1 that commits the fallacy here by grossly overestimating the actual likelihood of getting struck by a meteorite. We could call this a fallacy, but we could also call it a weak inductive argument. Fallacies tend to be the tricky mis-steps in the logic game which wind up being convincing. That is to say, we take pains to labels specific types of errors as certain fallacies because we need to train ourselves to avoid them.

We train ourselves to avoid fallacies because they don't work. If they worked more often than not then we would call them strong inductive arguments and happily employ them on a regular basis.

If fallacies worked we would embrace them. The precise reason why we take pains to identify and reject them is because we know from experience that they lead to unreliable conclusions. At best you might describe evolutionary endowed predispositions leading to behavior which might resemble actions resulting from fallacious reasoning (like instinctual bush paranoia vs concluding every bush rustle is a lion, or being addicted to the thrill of fishing vs the gamblers fallacy), but when we understand the logical or rational benefit of being a dedicated fisherman and a careful woodsman, we can re-frame the argument in such a way that it makes perfect sense without embracing either instinct or fallacy. How often do lions kill people by leaping out of bushes? Might want to consider not taking chances if the frequency is high enough. Never giving up fishing, during either a time of feast or famine, is always beneficial to long term survival where food is not guaranteed to always be available.

The rub here is that if you manage to present a rational argument which makes fallacious reasoning somehow beneficial to survival or other such goals, then it becomes rational to adopt the actions prescribed by the fallacious reasoning in a strictly logical and strategic way; not fallacious.

the clever ones ended up being devoured by lions — Sapientia

As well they should be. Where would predators be without stupid prey? One doesn't always feel like cleverly outwitting supper.

The problem is not how one reads books on logic. The problem is that the use of logic in the fall world is fallacious. Logic is only useful in the academic classroom and has no usefulness beyond that. The is simply no n way to state a factual proposition.

Of course being wrong has value. It is how everyone learns, grows, and evolves. It is absolutely fundamental to human existence.

Think Zeno's pardox. Logically/mathematically one CANNOT travel any distance. However one can easily walk from one place to another. This is a perfect example that our world and this universe itself is not limited in any way by our logic and its rules. That leaves plenty of room for perfectly applicable fallacious thinking. — TheMadFool

Yes, I agree. Bergson solved the paradox by observing that true time is continuous (non-divisible) and heterogeneous. Logic can never solve these kind of problems.

So fallacies do have a important practical use.

Everything has uses. They exist and if they exist they can be used for learning. But this doesn't mean that we have to learn from everything. We pick and choose.

No.

Everything has uses. They exist and if they exist they can be used for learning. But this doesn't mean that we have to learn from everything. We pick and choose. — Rich

Exactly. So shouldn't logicians be cautious about condemning a useful way of thinking? Fallacies are part of the repertoire of our survival skills.

It is always such a joy seeing people live up to their titles.

It is always such a joy seeing people live up to their titles — John

Ad hominem:D...a survival skill

I wouldn't say that fallacies are a necessary survival tool. I've pretty much lived my whole life without resorting to Aristotelian logic, syllogisms, etc. I recognized the weaknesses in this tool very early on in my first philosophy class (much to the consternation of my philosophy professor).

These are all just learning tools for people to explore. Every syllogism is fallacious ii one way or another. One takes away from it with what they wish.

Fallacies are part of the repertoire of our survival skills. — TheMadFool

Not fallacies per se, but rather types of reasoning other than deduction - e.g., retroduction (hypothesizing a plausible antecedent from an observed consequent) and induction (generalizing from individual cases).

The bushes rustling for instance is decidedly NOT fallacious when one takes into account overall survival strategy and the general context in which such a decision would be taken. If lions are known to leap from rustling bushes, even in only 1/1000 instances of bush rustling (it's rare for it to actually be a lion), it will still be quite rational to presume it is a lion for safety reasons and flee none the less. Depending on the prevalence of lions, bush rustling, and the combination of the two, it might be entirely rational for a person to assume that every bush contains a lion and for survival purposes burn them all down. The (proper) conclusion is actually that there is a chance that there is a lion in the bush, and based on the adequacy of that chance, a decision is made to flee or not flee based on probability (lacking a better term). Here the fallacy is not the argument or the conclusion, it's the very acceptance of the conclusion (in deciding to flee) when it is actually not strategically productive to do so (pertaining to the goals of the individual in question). — VagabondSpectre

In traditional logics, probability has nothing to do with it. Reasoning is fallacious if it doesn't guarantee validity, where validity is when it's impossible for the premises to be true and/or the conclusion false.

The point of this is that this traditional approach to logic isn't necessarily very useful when it comes to making decisions, acting, etc.There it's often wiser to act on educated guesses and so on. We need modified logics to handle such situations, if we want to treat them logically.

Reasoning is fallacious if it doesn't guarantee validity, where validity is when it's impossible for the premises to be true and/or the conclusion false. — Terrapin Station

Only in deductive reasoning. Retroductive reasoning is valid when it produces an explanatory hypothesis that is capable of experiential testing. Inductive reasoning is valid when it proceeds in such a way that it will be self-correcting in the long run.

In traditional logics, probability has nothing to do with it. Reasoning is fallacious if it doesn't guarantee validity, where validity is when it's impossible for the premises to be true and/or the conclusion false. — Terrapin Station

Inductive reasoning is still reasoning. We use it all the time. Instead of making its conclusion guaranteed and therefore sound as in deductive reasoning, inductive reasoning makes it's conclusion "strong" or more likely or probable without actually necessitating it.