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In the situations where Münchhausen trilemma is applicable, people tend to use a version of abductive reasoning, which is finding the simplest narrative or explanation that fits the known facts.

https://en.wikipedia.org/wiki/Abductive_reasoning

It's important to keep the Münchhausen trilemma and abductive reasoning in mind when discussion controversial issues where one side feels they have proof and the other side is ignorant or duped. Often the difference is something like whether emergent behavior or a conspiracy feels like a simpler explanation.

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abductive reasoning, which is finding the simplest narrative or explanation that fits the known facts.

The problem there, is figuring out what "simplest" means. To many people, "God" seems like the simplest explanation for the universe, even though what the word implies is very complex. It's the same phenomenon as people who say, "Scientists can't explain magnets, the liars!" Magnets seem like a magical extra, but it turns out that electromagnetism is a fundamental. It's a rock sitting on a tabletop that's complex and turns out to need explanation.

https://www.youtube.com/watch?v=fwMSaCrcAmM

We should teach abduction and Bayesian reasoning as part of a normal education. Epistemology overall is more of a collegiate/post-grad subject, but we have to provide some kind of foundation in epistemology. Otherwise we end up with a lot of kids who have tied their self-worth to knowing "science", but it's more of a slogan and catch-all phrase than something they can continue to build on. (Aside from the actual practice of whatever scientific field they end up in. Even then, we see in several fields epistemological problems rearing their heads -- and the leading practitioners clueless about what to do about it. Usually re-inventing the wheel in some ad-hoc fashion.)

I've no idea what abduction means in this context, and neither does my dictionary. Can anyone help?

Take the facts, and form the simplest theory that explains them. At least that's my take on it in this context.

https://en.wikipedia.org/wiki/Abductive_reasoning

Really good point on controversial issues. I think opposing sides of current hot topic issues (take your pick, gun control, abortion, pronouns) start with a different set of axioms. Axiomatic differences can lead of vastly different conclusions, both with sound logical reasoning.

Eg. If you take as axioms that it is always wrong to end life, and life begins at conception, abortion is wrong is a sound logical conclusion.

> Eg. If you take as axioms that it is always wrong to end life, and life begins at conception, abortion is wrong is a sound logical conclusion.

yes, and you'd also end up with an outright ban on civilian ownership of automatic weapons, amongst other safety measures. But you don't often see those two together. I think that the axioms are a layer or two below that, and might involve concepts like "individual responsibility" and "greater good"

Agreed; it seems likely that the axiom system of the typical pro-life defender[0] is closer to "It's always wrong to end an innocent life"; this requires the inclusion of a set of axioms defining innocence (and thus probably invoking some combination of free will, and an absolute moral axis. A convenient framework for this includes a soul). This way you preserve the ability to defend yourself, to take the life of an enemy soldier, etc, while still being able to justify a pro-life position. It also allows for the death sentence for murderers.

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0. there are, of course, different sets of axioms that arrive at superficially similar conclusions. For example, the category of pacifist that believes that any loss of life is not justifiable; this kind of person will reject both abortion and ownership of weapons, war, etc.

It could also be that either side of these debates are unknowingly using abductive reasoning for how they feel about a stance that conflicts. Perhaps the proposed axioms come after to explain how people feel about controversial issues.

Funny enough, this conversation could also be a form of abductive reasoning. We're inferring that people are using abductive reasoning because people often hold conflicting moral views, though using abductive reasoning wouldn't necessarily guarantee conflicting views.

> Eg. If you take as axioms that it is always wrong to end life, and life begins at conception, abortion is wrong is a sound logical conclusion.

Do note that often in this kind of controversial topics, the axioms are not held consistently by a given side (or the actual axioms are hidden and differ from the stated ones). For example, "it's always wrong to end a life [except when bombing abortion clinics | except when it's a death row immate]". Then the ad hoc provisions start, "oh, I meant an innocent life" ("but how can a nonsentient being be called innocent in any meaningful way?"), etc, etc. The debate then becomes anything but grounded on well defined axioms.

Well, the real mistake is believing that people think or behave in a consistent manner. All attempts at "rational" debate starts from this flawed premise, and thus always fails.

"All" and "always" are too strong. It's definitely possible to engage in rational debate with an intent to be consistent, and update one's own views when a conflict is discovered. It's just not universally done.

It's not even that they aren't held consistently. Honestly, nobody (outside of philosophy papers) lists out their axioms and derives beliefs. They have beliefs and "reverse engineer" the supporting axioms, and don't particularly care if the axioms required for one position conflict with the ones required for another.

Agreed, I don't think people really debate emotionally charged issues from first principles. I think it's an error to think of this as a matter of logical axioms. That's not how people (usually) debate.

Its obvious that logic isn't a good model for how people form and change opinions. (I just feel that it isn't)

So... what's the state of the art?

It's been out of favor since Derrida, but I think Structuralism is due for another pass in the limelight. An extreme subjectivism about reality, shaped by the stimuli you are exposed to. These external stimuli are what define your axioms, and from there, you use the same (fuzzy, bad, and prone to inducing contradctions) logic as everyone else. It provides a compelling model for why people have difficulty reconciling their opinions; they're not even talking about the same things, just using the same words, the same signs.

What is a belief but an axiom? A prior that must be assumed, as it cannot be proven within the system.

I will definitely concede that the logic people use on a day-to-day basis is much fuzzier than an analytic might prefer, and that there's much greater allowance for contradiction (see the phenomenon of Cognitive Dissonance). But I do think that most people argue from their own first principles, consciously or not. There are rare cases where you can convince someone of something when you discover and correct a logical flaw they have made. More often than not, though, a 'logical argument' is a veiled battle of dogma; both participants are moderately rational, and share the same rules of logic, but their axioms are so alien to eachother that what is plain as day to one is a violation of human decency to another. I'd reckon that in reality, it's rare that two people are actually even arguing about the same thing, even though they may be using some of the same words.

Very true. In fact, I don't think people even start out with "beliefs". They start out with feelings. The emotional response is the equivalent to an axiom, and is abstract and formless. They must use their life experiences to form a reasoning to justify why they feel a certain way, and that is their "belief". This justification is rarely entirely accurate, it's just an approximation filtered through their own biases and reasoning capabilities.

When I have an argument, I find it most productive to first seek out to understand how the other person feels. Peoples' feelings are rarely "incorrect", and usually align with my own feelings at some fundamental level, although perhaps with different intensities. I then try to work with them to put our brains and experiences together to find a more solid understanding for why we feel that way.

> "but how can a nonsentient being be called innocent in any meaningful way?"

This makes me imagine putting people through a trolley problem where you have a serial killer on one side and an 8 week old fetus [1] on the other. That said, many of the people I've known simply argue against the death penalty instead. This may be biased by knowing Catholics, though.

[1] https://www.babycenter.com/fetal-development-images-8-weeks

The validity of abductive/inductive reasoning is itself subject to the trilemma.

First, inductive reasoning is different than abductive reasoning.

Second, the goals of abductive reasoning are different than philosophical or mathematical proof. Often we need to make decisions on incomplete information, and it's a philosophy to help one do so.

For example, juries are supposed to make a decision based on a preponderance of evidence or beyond a reasonable doubt. Convictions would be rare if the standard were incontrovertible truth.

Of course, but the whole point of the trilemma is that absolute knowledge of absolute truth is impossible, not that we cannot axiomatically accept the utility of partial, approximate knowledge.

Also, while abductive reasoning is (a bit) different from inductive reasoning, they have the same underlying epistemological justification. In discussions of epistemology you often don't see abductive reasoning mentioned, as it falls under the general framework of inductive reasoning.

Well if absolute knowledge of absolute truth is impossible are you able to suggest a truth that could even be considered absolute? If not, bit of dangerous statement, isn't it?

That's the trilemma.

Uh, no it's not. You start with a statement then you go about trying to analyze it....? Ok.

Seems to be the same principle as Occam's razor [1] or am I missing something?

[1] https://simple.wikipedia.org/wiki/Occam%27s_razor

In spirit, yes. However, it gets more interesting if we try to make Occam's Razor more precise with something like Solomonoff induction, then it get's trickier to decide in practice what "simpler" actually means.

Even if we're able to reduce our competing models to Turing machine implementations, we're only able to calculate their complexity relative to some defined collection of models, which in turn depends on what kind of low-level logical formalism we're using.

In practice, of course, we can't parse out all these formal details for every decision, but I think it's helpful to at least be aware of the inherent problems with naive Occam's Razor.

Occam's razor is better thought of as a method of choosing between alternative explanations of the same observed phenomena. It suggests choose the one that requires the least unproved theoretical scaffolding to support it. It is not really "accept the simplest explanation" but more like "do not create complex theories unless they explain the facts better than the simple ones."

Still, Occam's Razor (or lex parsimoniae) :

https://en.wikipedia.org/wiki/Occam's_razor

tends to be a valid approach, generically speaking.

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