So rationality doesn't work as a decision guide. — unenlightened

That does not follow. Rationality is not an oracle guaranteed to lead to a truth. But rationality is more likely to lead to truth than irrationality.

We rarely have enough information to prove something true beyond all doubt, so navigating through life entails making informed, rational predictions and decisions. Occasionally, wild guesses work out, but informed, rational decisions are more apt to do so. Example: for any given vaccine, it's possible it will do more harm than good, but we can look at studies (or trust those who've done so) to weight the good vs the bad.

We rarely have enough information to prove something true beyond all doubt, so navigating through life entails making informed, rational predictions and decisions. Occasionally, wild guesses work out, but informed, rational decisions are more apt to do so. Example: for any given vaccine, it's possible it will do more harm than good, but we can look at studies (or trust those who've done so) to weight the good vs the bad. — Relativist

I would go a step further. It would be irrational not to do things the way you’ve described.

But rationality is more likely to lead to truth than irrationality. — Relativist

My rationality or yours?

:up:


You can only employ your own rationality, and I can only employ mine.

Your rationality is more likely to lead you to conclusions that are consistent with your background beliefs. If those background beliefs are true, they will be directed toward truth. The same applies to me.

Suppose you and I reach different conclusions. We could then both profit from having a discussion to identify differences in background beliefs and the reasoning we each employed. We may then adjust our beliefs and/or revise the sort of reasoning we employ.

Suppose you and I reach different conclusions. We could then both profit from having a discussion to identify differences in background beliefs and the reasoning we each employed. We may then adjust our beliefs and/or revise the sort of reasoning we employ. — Relativist

That is what we are doing - having a discussion. You have taken the bet, and I have rejected the bet and we have laid out our reasons. Now I hope you will agree that the actual outcome is not decisive in this case. neither of us is entirely certain in our estimation of the odds, and even if we were, we might still be unlucky. We could do a much more detailed survey of the number plates that pass @T Clark's house, to see if there are patterns in the data and what the relative frequencies are over time. And perhaps a psychological assessment would be helpful in determining whether he is an inveterate gambler with very poor judgement, or a kindly chap that wants to give away some money without causing the beneficiaries any embarrassment, or a trickster, or something else.

But as things stand, we have made different decisions based on different rationales and the information we have.
Therefore, rationality is not decisive in this case. And if it turns out that we are all turkeys, and tomorrow is thanksgiving, then our reasoning about the kindly farmer that feeds us every day will be completely and catastrophically wrong; and perhaps the sun will not rise tomorrow because we are living in a simulation that is about to be turned off.

But what I have not seen in all this pragmatism is any answer to Hume. His claim is that one of our "background beliefs" seems to be that the future will be broadly the same as the past, and this is something we cannot have any evidence of whatsoever because the future is always beyond our experience. It is therefore plucked out of the total vacuum of unknowability and it is on this literally unreasonable assumption that all this "pragmatic rationality" is founded.

This principle applies just as much to probabilities and statistics like car number plates as to the orderly procession of the heavens and the rising of the sun. 'These are the plates we have seen -therefore these are the likely plates we will see next. But the 'therefore' has ZERO justification in logic or evidence. It's called "The problem of Induction". This is what you are calling 'rationality'.

This is a truly bizarre argument. I give up.

Abandon (the pretence of) rationality, all ye who enter here.

Therefore, rationality is not decisive in this case. — unenlightened

But rationality WAS decisive for both of us. Contrast our rational choices with IRRATIONAL means of making a choice: basing it on the alignment of the planets, consulting a Ouija board, or basing it on an inscription in a fortune cookie.

neither of us is entirely certain in our estimation of the odds, and even if we were, we might still be unlucky. We could do a much more detailed survey — unenlightened

Yes, and that would have been even better, but in our example it's not worth the effort. In other cases, it might be worth the effort, but we don't have the time. But in all cases, we can make a rational choice based on the imperfect set of information that we have.

But what I have not seen in all this pragmatism is any answer to Hume. His claim is that one of our "background beliefs" seems to be that the future will be broadly the same as the past, and this is something we cannot have any evidence of whatsoever because the future is always beyond our experience. — unenlightened

Here's how I approach it: some explanation is needed for the constant conjunction of past regularities. I judge that the "inference to best explanation" for this is that there exist laws of nature that necessitate this behavior. Inferring a best explanation is rational - it's a form of abductive reasoning.

So what's the alternative? Remain agnostic based SOLELY on the possibility that there will be some future "black swan" event? What's wrong with that is that it is no more than a bare possibility (i.e. it's logically possible, but lacks evidence or any other rational basis for considering it more than that). If you're going to withhold judgement on EVERYTHING on the basis that it's logically possible that you're wrong, you'll be completely indecisive about everything in life. If you only apply this extreme skepticism selectively, then you are being inconsistent - which is irrational.

It is therefore plucked out of the total vacuum of unknowability and it is on this literally unreasonable assumption that all this "pragmatic rationality" is founded.

With the strictest definition of knowledge (belief that's true, and justified so strongly as to eliminate the possibility of being wrong), almost nothing is truly knowable - so it's a pointless goal. It's perfectly reasonable to commit on our judgments. Surely you do this in everyday life.

... some explanation is needed for the constant conjunction of past regularities. I judge that the "inference to best explanation" for this is that there exist laws of nature that necessitate this behavior. — Relativist

That is indeed a fine and attractive explanation for past regularities, and "as a rule" I myself have found that heads and tails come up about equally, and so on. But what leads you to apply this rule of the past to the future?

So what's the alternative? — Relativist

Indeed. And you call this 'rationality'? Not 'desperation'?

Here's how I approach it: some explanation is needed for the constant conjunction of past regularities. I judge that the "inference to best explanation" for this is that there exist laws of nature that necessitate this behavior. Inferring a best explanation is rational - it's a form of abductive reasoning. — Relativist

Check out Goodman's new riddle of induction if you haven't already. It's fun.

Look chaps, I can claim very little credit for any of this; it is seriously ill advised in my estimation to try and contradict Hume. he is The Man. He is not going to recommend that you abandon your science or your common sense. But he is going to ask you to abandon your arrogance and righteousness. Rationality is limited. It cannot manage on its own but stands in need of passion.

So what's the alternative? — Relativist

Attribute regularities to will rather than law, maybe.

That is indeed a fine and attractive explanation for past regularities, and "as a rule" I myself have found that heads and tails come up about equally, and so on. But what leads you to apply this rule of the past to the future? — unenlightened

Same answer: it's a law of nature, and laws entail necessity. I'll clarify what I mean by a law: it is a relation between two TYPES of things (or among several types of things). Electron A repels Electron B because it is a law that "-1 electric charges" induce that repulsion. Any instance of 2 electrons, anywhere in time, would necessarily have that effect.

So what's the alternative? — Relativist


Indeed. And you call this 'rationality'? Not 'desperation'? — unenlightened

Suppose you have a retirement account and you're trying to invest the money to grow large enough to enable you to one day retire. Would you consider taking guidance from astrology, fortune cookies, and California Psychics? If not, why not - if all "rational" choices are simply acts of desperation?

He is not going to recommend that you abandon your science or your common sense. But he is going to ask you to abandon your arrogance and righteousness. — unenlightened

This seems like kind of an arrogant and righteous comment.

So what's the alternative? — Relativist


Attribute regularities to will rather than law, maybe. — bert1

Why think that, other than that it's possible?

The thing is, it used to be a necessary truth, "All swans are white." Philosophers dined out on it for years. And then there wasn't 'a black swan event'; that could have been dismissed as a sport, an aberration, the exception that proves the rule or some such. No, there was a whole fucking continent of overtly black swans, unapologetically swanning about like they owned the place and had always been there. Cue much coughing and mumbling into beards.

He is not going to recommend that you abandon your science or your common sense. But he is going to ask you to abandon your arrogance and righteousness.
— unenlightened

This seems like kind of an arrogant and righteous comment. — T Clark

Yes, darling, but that's my comment, not Hume's.I am arrogant and righteous, so you can dismiss me with a casual projection like that.

Look chaps, I can claim very little credit for any of this; it is seriously ill advised in my estimation to try and contradict Hume. he is The Man. — unenlightened

Hume's view have been challenged by a number of philosophers. I'm just borrowing from them. A good exposition of this is in Causation (edited by Sosa & Tooley).
(A few years ago, I found a link to a PDF of it, so I have a copy).

Here's a link to an article by Tooley.

The thing is, it used to be a necessary truth, "All swans are white." Philosophers dined out on it for years. And then there wasn't 'a black swan event'; that could have been dismissed as a sport, an aberration, the exception that proves the rule or some such. No, there was a whole fucking continent of overtly black swans, unapologetically swanning about like they owned the place and had always been there. Cue much coughing and mumbling into beards. — unenlightened

"All swans are white" is a necessary truth if swans are defined as "white aquatic birds with long necks and xyz". But let's suppose someone inferred it a law of nature that whiteness was physically necessary in birds with some set of other characteristics. First, I wonder how that would be justified, but let's just assume there was a good justification. The discovery of a black swan would falsify that theory and lead to theory revision. What exactly is the problem with that? Would you toss out the teaching of science on the basis that every theory is provisional and there's always a chance it will be someday disproven?

But rationality WAS decisive for both of us. Contrast our rational choices with IRRATIONAL means of making a choice: basing it on the alignment of the planets, consulting a Ouija board, or basing it on an inscription in a fortune cookie. — Relativist

I’ve been thinking about this and I’m not sure you’re right. I guess it depends on whether he didn’t take the bet because he really thought the odds were against him or because Hume said he shouldn’t.

But what I have not seen in all this pragmatism is any answer to Hume. His claim is that one of our "background beliefs" seems to be that the future will be broadly the same as the past, and this is something we cannot have any evidence of whatsoever because the future is always beyond our experience. It is therefore plucked out of the total vacuum of unknowability and it is on this literally unreasonable assumption that all this "pragmatic rationality" is founded. — unenlightened

All the evidence we have points to the conclusion that the future will be broadly like the past. Hume was, in my view, merely pointing out that this is not a deductively certain conclusion. It is rational to take past experience as a guide to predicting what the future might be like, simply because there is no other guide.

It is not, to put it in Kantian terms, pure reason which is at work in this, but practical reason. Whether nature's apparent laws are truly necessary laws or merely acquired habits, it doesn't matter. Even if they are merely habits, it still takes a lot to change a habit, for us as well as nature. It is arguably more rational, in general although of course there are exceptions, to stick to our habits, provided they really are rational, that is well-considered, ones.

Overuse of resources, environmental pollution and habitat destruction do not count as rational well-considered habits, even though we may not be able to be deductively certain that they won't somehow magically renew themselves.

I'll just leave it there, and see if it appeals to anyone else. — unenlightened

It made sense to me. This same basic problems shows up for any metaphysics of sheer difference. If everything is completely different in each "moment" then you don't have "different moments" in any sort of whole, but just sui generis, unrelated "beings" plural. I think this applies for any attempt to eliminated causality as well.

I have a quote I like to use here, which maybe will find helpful:

Kant realized that Hume’s world of pure, unique impressions couldn’t exist. This is because the minimal requirement for experiencing anything is not to be so absorbed in the present that one is lost in it. What Hume had claimed— that when exploring his feeling of selfhood, he always landed “on some particular perception or other” but could never catch himself “at any time without a percepton, and never can observe anything but the perception”— was simply not true.33 Because for Hume to even report this feeling he had to perceive something in addition to the immediate perceptions, namely, the very flow of time that allowed them to be distinct in the first place. And to recognize time passing is necessarily to recognize that you are embedded in the perception.

Hence what Kant wrote in his answer to Hamann, ten years in the making. To recollect perfectly eradicates the recollection, just as to perceive perfectly eradicates the perception. For the one who recalls or perceives must recognize him or herself along with the memory or perception for the memory or impression to exist at all. If everything we learn about the world flows directly into us from utterly distinct bits of code, as the rationalists thought, or if everything we learn remains nothing but subjective, unconnected impressions, as Hume believed— it comes down to exactly the same thing. With no self to distinguish itself, no self to bridge two disparate moments in space-time, there is simply no one there to feel irritated at the inadequacy of “dog.” No experience whatsoever is possible.

Here is how Kant put it in his Critique of Pure Reason. Whatever we think or perceive can register as a thought or perception only if it causes a change in us, a “modification of the mind.” But these changes would not register at all if we did not connect them across time, “for as contained in one moment no representation can ever be anything other than absolute unity.”34 As contained in one moment. Think of experiencing a flow of events as a bit like watching a film. For something to be happening at all, the viewer makes a connection between each frame of the film, spanning the small differences so as to create the experience of movement. But if there is a completely new viewer for every frame, with no relation at all to the prior or subsequent frame, then all that remains is an absolute unity. But such a unity, which is exactly what Funes and Shereshevsky and Hume claimed they could experience, utterly negates perceiving anything at all, since all perception requires bridging impressions over time. In other words, it requires exactly what a truly perfect memory, a truly perfect perception, or a truly perfect observation absolutely denies: overlooking minor differences enough to be a self, a unity spanning distinct moments in time.

William Eggington - "The Rigor of Angels: Kant, Heisenberg, Borges, and the Ultimate Nature of Reality."

It makes a bit more sense if you're familiar with Borges' story Funes the Memorious though. The basic idea is a guy who can remember everything perfectly. He can spend 24 hours remembering and basically relive the same day at will. Because of this, he finds language incredibly inefficient and confusing. Why speak of "clouds" when you can speak of "that particular cloud on the morning of November 8th, 1928?" And why speak of that same cloud early in the morning before the sun hit it as the same thing as the cloud once the sun illumined it? They can all be held absolutely distinct.




The fact that skeptics don't act with the courage of their convictions has been pointed out since ancient Greece and India, but I am not sure if this diffuses the general challenge. The skeptic's point is not generally that we ought to go walk off a precipice, etc. In practice, they normally use the impossibility of justification "pragmatically" themselves. For example, if one thinks it is impossible to ever justify any claims about morality and ethics, it's pretty easy to use this skepticism selectively in self-serving ways. In many ways, absolute misology is less threatening than "pragmatic" misology. The former, a sort of absolute epistemic nihilism, is at least obviously ridiculous. The true ruin of reason lies in selective adherence. That's why I think appeals to "pragmatism" can often be the worst sort of solutions to skepticism.

At any rate, this sort of skepticism comes up in plenty of places. The Boltzmann Brain and various variants, particularly those involving a "Many Worlds Hypothesis" are a good example where the conclusion of radical skepticism can come through surprising paths. But of course, these also tend to be self-undermining in that, if we think we are likely to be "randomly generated" we ought not trust this very belief itself, since random beliefs will not tend to be true given that there are always vastly more ways to be wrong than right.

A genuine miracle is occurring — a supernatural violation of natural laws, or I am probably in a universe (within an infinite multiverse) where an extraordinarily improbable natural fluctuation — say, a “Boltzmann fish” scenario — has spontaneously produced the fish.

If I I think I probably live in a multiverse, which explanation would Hume think I should favor? — RogueAI

Ha, a good question! If you begin to see miracles, even deeply personal ones, you should probably just accept that these necessarily happen in some part of the wave function with a probability of 100%, so why not "here?" Likewise, quantum immortality is a reality, so you probably should be concerned about ending up in one of the innumerable paradise timelines instead of the damnation ones (not that you can help it, both will inevitably happen, regardless of your sins or karma). It also follows that Jesus certainly did rise, "somewhere," so there is that.

Lots of silly things result from Many Worlds. That it has become popular as a "solution" to the Fine Tuning Problem to me is sort of baffling. To my mind, it represents an essentially religious commitment to the essentially aesthetic ideals of "naturalism" to posit "everything possible happens" as a solution to the threat of life seeming vanishingly unlikely otherwise.