Posts Tagged 'hypothesis'

Does Logic Settle The Issue?

Bog-Hubert, entering the Fog Island Tavern, tries to get the attention of Tavern-keeper Vodçek, who is bent over a piece of paper on the counter, scribbling notes in its margin.

– So my friend, are you embarking on a new career of literary critic, or editor? What august publishing entity are you working for?

= Huh? Oh, sorry, didn’t hear you come in. What’s that you say about career? Or did you mean a beer?

– No, thanks, coffee would be fine. I was curious about your editing work there.

= Oh, this? It’s just a letter to my grand-aunt that came back as ‘undeliverable’.

– Your grand-aunt? Hasn’t she been dead for quite some time already? The one and only Aurelia Fryermouth? or do you have another equally grand aunt?

= No, that’s the one. And yes, she died many years ago. Here’s your coffee.

– And your letter took this long to get back to you? I knew the postal service to that country was kind of, well, unpredictable, but this…

= No, I wrote this about a month ago, and it just came back.

– Of course, if she’s dead. Stands to reason. But now you have me seriously worried. Why in three twister’s name did you write her when she’s dead?

= Oh, I do that all the time. I used to write her whenever I’ve written something I’m not quite sure about, and she always sent me useful, insightful comments back. So now I do the same thing, and when the letters come back after a while, I imagine her comments and write them in the margin, with my comments and rebuttals. Using a four-color Bic to keep track of what’s what. Very useful.

– The Bic? Okay. But this strange habit?

= Don’t knock it, it has kept me out of a lot of trouble. It should be required of everybody who’s writing, especially folks who write all those comments in social media discussions.
Now I admit, not everybody has an aunt Aurelia whose wisdom, even of the imagined kind, can be of such profound quality and assistance. She had a way of cutting through the distractions and BS, and put her finger on the real sore spots, like no teacher I ever had. But just imagining what she would say — just like those so-called conservatives who keep parroting ‘what would Reagan do?’; they really should look for somebody more … well, let’s not get into that — is immensely helpful. Not to mention the time delay. Remember the old advice to ‘sleep on it’ before jumping into action? One night is not enough, my friend. Looking at your impulsive writing after several weeks, during which you may also have gained some extra insights and wisdom, however infinitesimal, given your age (compared to aunt Aurelia’s), can be a very sobering experience.
– Ah. I see. It explains the wide margins you’ve left in the letter. But how to you ensure that your margin entries are not as impulsively imprudent as the original writing?

= Good point. I can only say there is a marked marginal improvement, if you’ll excuse the puns. And I indeed have at times resorted to sending her my comments back for review and revision… She does not mind that, unlike live editors who have a tendency to react with irritated and, if I may say so, rather impolite retorts to even the slightest challenges of their authority.

– Hmm. I admit, it sounds like a wise routine. Widely adopted, it would save humanity from a lot of, — what did you call it? — ‘impulsive’ writing, I agree. But now you have made me curious: what are those profound questions you have her comment upon from the Great Aurelian Beyond?

= Don’t know about profound. This last one was just about the puzzlements I felt about the offer by the climate scientist Dr. Keating, to pay a considerable sum of money to any ‘denier’ (his term) of man made climate change to provide a proof, via scientific method, that man made climate change does not occur.

– I heard something about that, yes. Did he get any such proof?

= Several dozen, as far as I know. So he had a big discussion on his blog about why the proofs didn’t hold water, and responding to all the folks who didn’t think the challenge was serious, or ill-stated etc.

– So what about your puzzlement?

= Well, there were several. One was about the reasons why some people seem very reluctant to accept the idea of man made climate change, (MMCC) for reasons they couldn’t really discuss because Dr. Keating insisted on it all being ‘scientific’. But even if they weren’t, does that mean they were totally illegitimate and nonsensical? For example, could it be that — for Dr. Keating and others — accepting the MMCC hypothesis would be seen as also accepting some implications, sight unseen, that might very well be worthy of discussion?

– Okay: seems worth looking into. The other issue?

= That was a strange one. In the discussion, both parties were at times insisting that they had valid logical reasoning on their side, and that the other side was guilty of violating logic. Now somebody found this a bit curious, not to say logically questionable. But upon investigating the matter, he found out that if you just looked a the logical validity of the arguments people put forward — not the truth or probability of the premises — it is entirely possible for both sides to propose quite logically valid arguments for their case, while also being vulnerable to accusations of using arguments that are not deductively valid but perhaps merely ‘plausible’, but logically inconclusive.

= Huh. Can you explain that?

– Sure. Take the main scientific argument abut a hypothesis H — in this case, that MMCC is true. You examine the hypothesis and find that if it is true, then we should be able to find some evidence E that must occur as a consequence. That makes the first premise “If H then E must be observed” or H –> E. Now we observe E. Does this ‘prove’ that H is true?
No: it is the inductive reasoning scheme
((H –> E) & E) –> H
which is logically inconclusive, not deductively valid. It’s what they call a ‘just another white swan’ argument: observing any number of white swans — E — does not prove that the hypothesis that all swans are white is true. (If true, it implies that all swans observed will be white.) You can test that with a truth table: there is one case among all the possible states of the world involving H and E that makes the main implication ‘false’. So if that is your main argument for H, you can be accused of using less than deductively valid logic. But observing just one black swan (or even a pink one, for a more colorful discussion) ~E, deductively, validly refutes the hypothesis:
((H –>E) & ~E) –> ~H
This is a perfectly valid deductive argument (called modus tollens by the logicians).

= I remember that now, yes. But in science, they have developed that trick with the ‘null hypothesis Ho’ — the hypothesis put on its head — haven’t they? And use the same modus tollens argument showing that if E is observed, Ho can’t possibly be true?

– Yes, at least for questions involving large numbers of data observations, where Ho is understood as e.g. climate changes happen at random, unrelated to human activities. Then the argument is not claiming total refutation, just that it is so unlikely (having such a low probability) that E could be observed of Ho is true, that Ho is rejected, and provisionally H is accepted instead. This is accepted as valid scientific reasoning.

= So If they can produce such evidence and arguments, doesn’t that settle it?

– Not so fast. For one, the argument scheme is a different one, depending on whether you accept or reject the premises. Which are of course part of the controversy. And the evidence E is not a simple observation or experiment result, but consisting of a ‘body of evidence’ that starts with the definition and understanding of the things you are discussing. Say: what qualifies as ‘climate change’, what human activities are influencing climate. Then selecting appropriate variables for those concepts, that must be measured: temperature; okay, or CO2 — but of what? air? water? land? some combination? measured how, over what time period, where? (e.g. on the surface? or in the stratosphere, or somewhere in-between? Then there must be some distinctive and significant correlation between the measures for climate change and human shenanigans, and some provisions that the correlation actually indicates causation and not the other way around.

= Wait a minute: ‘the other way around’ — what do you mean by that?

– Oh, maybe somebody claims that human activities increase CO2 levels in the air, which change the climate. And somebody else says: wait — the climate is actually cooling, — the winters are getting colder, which causes humans to do more heating, which maybe increases CO2 somewhat, but the cause of that is really climate cooling? Even if the argument doesn’t make sense to you, you can’t just dismiss it as unlogical, you have to make sure that if you see a correlation between man-made CO2 and climate change, you have the cause and effect going in the proper direction.

= All that puts quite a burden on the scientists who claim there is a connection between climate change and human activities.

– Right. They have to provide solid evidence and arguments for all the components of that body of evidence. And it makes it relatively easy for anybody to challenge that hypothesis: they only have to put reasonable doubt on one single component of that chain of evidence, to turn the corroborating argument H –> E and E into the modus tollens
((H –> E) & ~E) –> ~H (‘black swan’) argument ‘refuting’ H. Allowing the ‘denier’ to claim a deductively valid argument.
But: What if somebody came up with an argument like this one: “((E –>H) & E) –> H”
(“If we see evidence E, this must mean that H is true; now we observe E, so H is true”)

= Huh? is that the way science works?

– That may be up for discussion. You could argue that this is precisely the way scientists come up with — conjecture — the hypothesis: they see some things E that suggest H. Science of course also insists that such observations must be repeatable and confirmed bu other observers etc. But if somebody makes such a case, they can claim a perfectly logical and deductively valid argument — a respectable modus ponens. Remember, whether the conclusion is true depends on the validity of the argument scheme and the truth or plausibility of the premises. To claim logical validity you don’t have to also claim truth of premises. But of course you can’t jump to any specific conclusions yet.

= I see the problem here: both sides can claim to have logic on their side. So logic by itself does not settle the controversy. Now if you accept that, shouldn’t both sides agree that the final conclusion will rest on both logical validity and true premises, and to then refrain from trying to clinch the case by just claiming valid logic?

– You’d think so. And youd’ think that the scientist would make that clear in stating his case, wouldn’t you?

= Sure. So?

– So part of my puzzlement was the reaction by Dr. Keating to somebody pointing out this story of both sides claiming logic. He just dismissed this, writing that ‘logic is just a tool’, what counts is valid science. Here little ol’ me always thought that valid logical reasoning, together with confirmed observation, correct measurement, calculations etc. was an integral part of scientific method, the science toolkit. What do I know…

= I can see where this might be a puzzlement for you. So what does your grand-aunt Aurelia have to say about all this?

– She jumped right on the first one of my puzzlements: the other, perhaps ‘illegitimate’, or non-scientific reasons people might have for hesitating to accept the hypothesis that human activities are screwing up the global climate. That perhaps the context of challenges and claims, like the one by Dr. Keating, subtly or not so subtly implies acceptance of some conclusions that are quite partisan and political, but that can’t be entered in this discussion because they are not ‘scientific’.

= I’m sure that may not be intended by Dr. Keating and other climate scientists?

– Sure — but it may be in the minds of some folks out there. And that makes them look for any little chinks in the body of evidence they can find.

= What are some of those implications — did you revered grand-aunt suggest some?

– Her main point was this: if man-made climate change is true, it raises the question whether we actually can do something meaningful about it, and if so, what. But they suspect that the scientists — calling them ‘alarmists’ in return for being called ‘deniers’ by Keating and others — already have an agenda of proposed strategies and rules up their sleeve. And that those will be very expensive. Even worse: that many people will have to change some of their cherished habits regarding energy use. And –psst– that some folks who are now making fine profits from conventional energy sources and life habits will lose those profits. The worst, though: that those new strategies will allow o t h e r guys, not them, to now make more profit. Utterly unacceptable, that one.

= Ahh. Of course. It may also be the fact that the costs of the new strategies will have to be paid ‘now’ or ‘soon’, obviously by people who now have or make money, by way of taxes — but that the profits or benefits will manifest themselves much later, in terms not of cash revenues but avoided disaster. So does that answer your concerns?

– You mean can I sleep better at night for these insights? Don’t think so. But I think that it might be better if those issues would also be put on the table and discussed, negotiated. Perhaps such questions could be more productively dealt with if they were stated differently.

= What do you mean — does it matter how a problem is stated to answer what we should do about it? A problem is a problem is a problem, after all…

– No, I think the way they are thrown up for discussion does matter. For example, consider raising a challenge about the climate change in the following way: Look at a table showing — I’m simplifying now, perhaps dangerously so, but just to make it clear — the possible answers to the MMCC question as columns: is MMCC real, or is it not (or so insignificant that we don’t have to worry about it), and our strategies as rows: do we do something about it, or do we not?
There will be four main outcomes, the boxes 1,2,3,4. For each one, there are three major questions that should be answered: a) what will happen? What will be the consequences? b) What, if anything, will be done? and c) depending on what is done, what is the likely result? That would allow the discussion to address each question separately and more explicitly, and perhaps make it easier to reach some decisions. If decisions are needed. And if they are, avoid wasting more time by quibbling about issues like proof or disproof of MMCC (which is a wrong question in itself because it’s not a yes-no question but one of relative significance and relationships between many variables).

= So what does your table look like?

– Here’s a first simple draft, for filling in the boxes and discussion: What if:

MMCC is:                              real & significant                   not real or insignificant ____________________________________________________________________________

We decide to                                     1                                                         2
take steps

We do nothing, or                           3                                                         4
continue what we do

= You might add another question there, my friend.

– Sure, there will be many more as people start talking more thoroughly about it. What’s the question you have in mind?

= It has to do with responsibility. Or accountability, if you wish: Who will take on the responsibility for decisions? And be accountable — whatever that means, which should be discussed more carefully — if it’s the ‘wrong’ decision?

– Huh. I need to send this back to aunt Aurelia. With wider margins…