18 April 2022

Who is the better altruist?

Hede: I recently made a donation of $1,000 to a charity and I'm feeling pretty good about it.

Hart: Really? I recently made a donation of $1,000 to a charity too. Which one did you donate to?

Hede: I gave $1,000 to a charity that provides cost-effective treatment against parasitic worms that plague many people in Africa. I did a fair bit of searching for the most effective charity, and chose this one as it has the greatest impact on people's lives per dollar invested. How about you?

Hart: I gave $1,000 to a charity that provides cuddly teddy bears to sick children in hospital. I was watching this documentary about sick kids, and when I saw what this one charity was doing, well, I just cried. I called them immediately after the program ended to make a donation.

[Adapted from a scenario created by Tadeg Quillien 2022]


- - - - - - - - - - - - -


Who is most concerned about the outcomes of her altruistic act, Hede or Hart?

Who is the most genuine in her altruistic intention

Who is the better altruist out of Hede and Hart? Why?

Who is more likeable person? Why?

What are the most important features of 'good' altruism? Effectiveness? Compassion? Something else?



"Is virtue-signalling a vice?" Tadeg Quillien (2022) https://aeon.co/essays/why-virtue-signalling-is-not-just-a-vice-but-an-evolved-tool 

Effective Altruism: https://www.effectivealtruism.org/

Ethics of care: https://en.wikipedia.org/wiki/Ethics_of_care

Compassion & altruism: Steno (2015) https://www.sciencedirect.com/science/article/pii/S2352154615000261  


31 March 2022

Idol Words on the meaning of life

Image from Le Magasin Pittoresque, 1839

[The following is an extract from "Idol Words" by Scott Alexander at https://astralcodexten.substack.com/p/idol-words] 

"Hello, welcome to the temple of the three omniscient idols, one of which always tells the truth, one of which always lies, and one of which answers randomly. I know you already signed the release form, but I’m supposed to remind you that we are not legally responsible for any consequence of following the false idols’ advice. Do you have a question?”

09 March 2022

Outrage is litter


Outrage is litter 

that sullies the 

moral landscape


-- Ssh

02 February 2022

On judging judgments


Be gentle on the judgments of others;

And be mindful of your own!


  -- Ssh

23 January 2022

Doctors debating vaccination

Dochotomy by MsLil (2021)
(This article is a L-O-N-G read, and it is incomplete. Constructive comments are welcome.)

The ground rules for the debate

Dr Provax
: Greetings fellow doctor, what do you know?

Dr Novax: Afternoon doctor. What do I know? Not much. Well, not entirely true. There's one thing I know: I'm done with the continual coverage of COVID. It's been two years now.
Dr Provax: Agreed. And with the latest variant, and two years to prepare, it is time for nature to show the non-vaccinators the folly of their reasoning.

Dr Novax: Ah, so you're vaccinated?

Dr Provax: Absolutely. You're not?

Dr Novax: No.

Dr Provax: Oh my God, why not? You’re crazy. We need to stop you anti-vaxxers before you kill us.

Dr Novax: Whoa, whoa. We’re friends, so I’m happy to have this discussion, but only if we have ground rules.

Dr Provax: What ground rules?

Dr Novax: Let’s refrain from invoking any unproved metaphysical entities such as God who are unnecessary to the discussion here. No ad hominem -- meaning you can attack the argument, but not the person. Calling me 'crazy' is ad hominem. And try to wind back the hyperbole such as your presumption that I am an 'anti-vaxxer', and your exaggeration that non-vaccinators will kill everyone. Everyone? That seems a lot strong: for one thing, if the vaccine is protective, then the vaccinated ought not be especially threatened by the non-vaccinator’s choice.
Dr Provax: Ah, yes, ok. I hear what you’re saying. Sure, tell me why you’re choosing not to vaccinate.

Uncertainty & misrepresentation

Dr Novax
: Well, we simply don’t know enough about the vaccines. The longest has only been in existence for coming on two years. We do not know the long-term effects of the vaccine.
Dr Provax: Well, I’ve vaccinated, and I haven’t grown a second head or a third arm.
Dr Novax: Ha, clever. No, you have not, or at least, not yet! What if it makes people sterile, or leads to premature death. What about the "unknown unknowns"? What might be is surely uncertain.
Dr Provax: True, but the scientists are tracking for all adverse events, and to present, none of your fears are being realized.
Dr Novax: Well that’s just not correct. There are reports that some of the vaccines do cause serious adverse events, even death. Of course, the authorities aren’t very forthcoming about that.
Dr Provax: Well, they’re focused on the adverse consequences of COVID itself: the roughly 30% who will suffer long COVID (UNSW study & PLOSMedicine), the roughly 10% who are hospitalized (Aust Govt Report), and of course, the proportion that will die. How come you’re more scared of the vaccine than the disease itself?
Dr Novax: You are quite correct, they are focused on the consequences of COVID. However, I just don’t see the disease as that scary. Coronaviruses are mostly harmless, they give humans colds.
Dr Provax: You're right, most coronaviruses are not deadly. But some are. COVID, MERS and SARS are all caused by coronaviruses and all are deadly.
Dr Novax: Well I've heard experts say that COVID kills no more than a regular flu.
Dr Provax: Look, you’re entitled to your own interpretations, but not to your own facts*. The annual flu in its worst forms kills about 300-600 thousand people worldwide (WHO), and in most years less. COVID has killed over 5 million people in just two years. My interpretation of that fact, my opinion, my speculation is that it could have been worse if the world had not implemented social distancing, masking, isolation and vaccinations.
(*See Hannah Arendt: "Freedom of opinion is a farce, unless factual information is guaranteed and the facts themselves are not in dispute." Truth & Politics, 1967)
Dr Novax: My interpretation of that fact is that it is over-reporting by including people who have died with COVID rather than of COVID.

Dr Provax: Ok, let’s agree the number might not be exactly right. There is probably over-reporting as you're suggesting. But there is evidence of under-reporting too, so let's accept the five million over two years as a useful starting point. We can then see that two million or more people per year is over three or four times the rate of annual flu in a bad year, and that has been the rate over two consecutive years.

Dr Novax:
Well, I’ve heard that over 99% of people with COVID survive.

Dr Provax:
Well, I’ll accept that is correct, but point out that saying 99% fatality-free is like saying 99% fat-free. It may make you feel better, but it doesn’t change the fact that the balance is an undesired alternative. Let’s say it as it is: it appears that there are one to two deaths for every 200 people infected with COVID (0.5-1% IFR).

Dr Novax
: Yeah, well the authorities will use exactly the same spin when they say that "COVID vaccines are safe and effective" (CDC). The truth that they are not 100% safe and not 100% effective is buried much further down. Ignorance is bliss – especially for those disseminating the ignorance.

Dr Provax
: Perhaps this is understandable as an effort to encourage people to vaccinate. We know that negative events, even rare ones, will put people off. Just the same way that shark attacks scare people out of the water, and remain a perpetual fear in the minds of tourists visiting Australia.

Dr Novax:
Understandable maybe, but it sounds like it is dubious ethically: exaggerate to get people to do what they want. I do not see that good intentions are sufficient to justify unethical behaviour. But really, I just don't understand. If the medical scientists are so smart, why don't they create something that strengthens our immune system?

Dr Provax
: Well, that's what vaccines do. They provoke the immune system to respond to a relatively harmless molecule that helps prime the immune system ready to respond to the virus. It is kind of like practising tennis by hitting a ball against a wall. It's not the real thing, but it helps.

Expertise and misinformation

Dr Novax: There’s just so much information, and it keeps changing. Wash your hands, oh that doesn't help much. Wear masks, oh they don't help unless you’re wearing the latest and greatest version. Vaccinate with Astra Zeneca if you're over 60; oh no, only if you're over 50. Oh there’s a new variant, and now you have to go and get another shot because two doses of the first vaccine offer only limited protection. But wait six months before getting the booster, or no, make it five, no four months. And so it goes on. How is someone meant to know what to believe?

Dr Provax:
In fairness, COVID is new, less than two years old. We're learning as we go along. It's a case of constantly updating to the latest and best knowledge.

Dr Novax: Precisely. We didn’t have perfect knowledge in the past, we can't be sure that what we think we know now is correct, and better knowledge may emerge in the future. So how does one decide what to do?

Dr Provax
: Well, you can try and evaluate all the information, but that would require years of expertise. And those lay people who claim to know something that everyone else has missed are very unlikely to be correct. So I guess we have to use the tried and true short-cut of trying to assess the credibility of who is talking.

Dr Novax
: So trust the experts? Even the experts disagree. There are lots of doctors who are saying things that are quite opposed to the views of others.

Dr Provax:
Yeah, well there are doctors and doctors. My philosophy doctorate and your credentials as a doctor of chiropractic limit our authority to speak relative to experts in immunology. Even then, there are likely to be some with more relevant expertise in virology and vaccines than others.

Dr Novax
: Well, there are experts who are nurses and academics and professors who are all throwing out conflicting opinions.

Dr Provax
: Yeah, but that is virtually true by definition: an expert opinion is one that is opposed by at least one other expert opinion. We do not need experts to tell us something largely uncontested such as the earth goes around the sun. An expert is someone at the frontier of knowledge. And the frontier of science is a kind of wild west where what is true is much disputed. So I guess that the safest choice is to simply go with the majority expert opinion.

Dr Novax
: Ha, but some of the most significant advances in knowledge come from someone, often a minority, overturning an older dogma. To use your example about the earth going around the sun, the majority expert opinion before the 1500s was the opposite, that the sun went around the earth. It took a string of individuals like Copernicus, Giordano Bruno and Galileo to convert the majority of experts to thinking the way we now think is the truth. Copernicus dodged ridicule and worse by stalling publication of his heliocentric ideas until his death. Bruno was burned for his beliefs, and Galileo spent years under house arrest for his beliefs.

Dr Provax
: True, and so this could be one of those occasions where the minority has it right. But the occasions that the minority is right are rare: the vast majority of minority views turn out to be false. Minority views are right only a minority of the time.

Dr Novax:
My concern is that all the voices speak with confidence that belies the uncertainty. The public health and government agencies speak authoritatively, even while best medical advice keeps changing.

Dr Provax
: Perhaps, but the alternative is ‘fake news’ from social media platforms like Facebook and rebel news sites. They tell a good story as reflected in the fact that they are passed around so successfully, but they ain’t true. A lie can fly halfway around the world while the truth is still lacing up its boots: falsehoods fly, truths trudge.

Dr Novax:
Ah, but from the layperson’s perspective, there is little to distinguish ‘fake news’ and ‘expert opinion’. Some people believe fake news, some believe expert opinion. Both speak authoritatively, yet both might be wrong. Ironically, the advantage of fake news is that it doesn’t change its mind! Fake news offers a certainty that is refreshing because the past two years of uncertainty feels just awful (Claire Wardle).

Dr Provax:
Which simply reinforces that knowing the truth takes an effort. And if you’re not prepared to put in the effort, then probably best to go with the authorities.

Dr Novax:
Except that the authorities speak stridently and authoritatively, signaling a certainty that they simply do not have.

Dr Provax:
Again, necessary in an effort to offset the strident, authoritative tone of the fake news.

Dr Novax:
Great, so both sides double down on their conviction, and both might be wrong. It appears no-one is going to win the battle based on information. We are being called on to make a decision, yet we agree that our knowledge of outcomes is uncertain.

Dr Provax:
Well, yes, you have to commit to some action. At some point, inaction becomes a decision to do nothing, and therefore, to bear the consequences.

Dr Novax:
So in an environment of too much information, much of it false or potentially wrong, it is hardly surprising that people simply decide what to believe, then try to find information to support what they believe rather than the other way around.

Dr Provax:
Yes, well this is the well-known confirmation bias. We tend to find information to support what we believe rather than build beliefs from information.
Dr Novax: And of course, we're all subject to confirmation bias, both those for and against.
Dr Provax: Yes, that is a fair assessment.
Mandated Vaccination

Dr Novax: So my problem is that despite this uncertainty which we appear to agree on, the government not only makes policy that we should all vaccinate, but is also making policy about restrictions on what we can do if we are not vaccinated. They are making vaccination compulsory.

Dr Provax: Hang on, they're not making the vaccination compulsory. Education is compulsory - everyone has to go to school no matter what kids, their parents or others want. That's compulsory. Taxes are compulsory - and that's good for all of us as it funds the health system that cares for our health - including public vaccination programs. Voting is compulsory – in Australia at least. Prison is compulsory - if it's ordered by a judge. And if a war comes along, men aged 18-22 might be conscripted to go into national service. Vaccination is not compulsory, but your ongoing job as a chiropractor may be dependent on being vaccinated. That's conditional rather than compulsory.

Dr Novax
: Okay, but it doesn’t seem right that they can simply make things ‘conditional’ as you call them.

Dr Provax
: It doesn't feel right when new conditions are imposed, but we live in a society governed by conditions designed to protect the common good. And you probably support many of these conditions. My profession as a university lecturer requires a string of degrees, your profession as a chiropractor requires certain qualifications. These are an effort to at least partially protect individuals in our society from charlatans. There are many other conditions imposed, again in an effort to protect other, maybe vulnerable, individuals in society. If you want to drink alcohol, it is conditional on your being over the age of 18. If you wish to drive a car, it is conditional on your being over 17, and licensed, and in a registered, roadworthy vehicle, and that you use a seat-belt, and you do not use your phone while driving, and your blood alcohol is under .05, etc.

Dr Novax
: The government is using this opportunity to increase their control over us. It is Orwell's 1984.

Dr Provax
: The governments is trying to do one of the jobs for which it is appointed, to protect us from threats against the common good. We are in uncertain times with a current threat looming, and they impose conditions for the good of the many. They don't necessarily get it all right, but they are acting quickly with a hope of saving more lives. During the Spanish flu outbreak in 1918-1920, quarantine, social-distancing, lock-downs, masks were all used - and publically opposed. Public health measures are always somewhat controversial but encouragingly, during the Spanish flu, those that did implement protective measures early appeared to be more effective. And to your fear of ongoing government control, are you not encouraged that the restrictions imposed during the Spanish flu were relaxed and only recently re-imposed some 100 years later.

Dr Novax:
Ok, so I agree that conditions are a part of living life in a civilized society. But why are they being imposed on my job. Why are they imposed on my going out to a bar or a restaurant? What is the risk posed by someone who is not vaccinated?

Dr Provax:
Well, an unvaccinated person might infect a vaccinated person.

Dr Novax:
As I understand it, with the latest variant, both vaccinated and unvaccinated persons can be infected, and can therefore infect others.

Dr Provax:
But the unvaccinated are more likely to be infected and therefore more likely to infect others.

Dr Novax:
Imagine it this way: if the vaccine worked perfectly, the unvaccinated would pose no concern at all as the vaccinated would be protected. However, the vaccine works imperfectly. And this has become the non-vaccinator’s problem. Why is that?

Dr Provax:
Well there is another problem, the unvaccinated who get infected seem more likely to end up in hospital and need more care on average than those who are vaccinated. That means our socialized health system has to pay for their choices. I do not think it is unreasonable that non-vaccinators must bear the personal consequences of their decision to not vaccinate. If you fall sick with COVID and need hospital treatment, you will be at the bottom of triage, and must pay for your treatment as in Singapore. Or perhaps, as a non-vaccinator, you ought to be willing to pay a higher health insurance premium say like a smoker. Are you as a non-vaccinator prepared to pay more for your health care if you are infected by COVID?

Dr Novax:
Well, maybe, but first, I want to push back on the idea that somehow my personal choices should exclude me from public health treatment. Young people are notoriously more likely than older people to engage in dangerous activities – driving dangerously, riding motorbikes, engaging in extreme sports but we do not exclude them from public health care. We allow people to make choices in our society, even ones that might result in harm to themselves. So if we’re going to be consistent, then we have to allow non-vaccinators access to health care like others. And again, I would highlight it is still relatively rare that these people will need care.

Dr Provax:
The choice to not vaccinate generates a higher cost, so the non-vaccinators must be prepared to make a bigger contribution.

Dr Novax:
Perhaps they do generate a higher cost, but how high is that cost in relative terms? Again, people make lots of choices, and some people cost our society more than others because of their choices, even illegal or disapproved choices like drug-taking, smoking, alcohol consumption, etc. They still have access to health care. Besides, businesses are crying for workers and customers to keep our society going – for the common good. How does it serve the common good to have an unvaccinated person blocked from the workplace and the market, and made a welfare recipient?

Dr Provax:
Hmm, well perhaps it is an effort to encourage people to vaccinate.

Dr Novax:
I’m fine with encouraging people to vaccinate, but like any marketing effort, I baulk when the marketing effort uses more coercive force. As I said before, good intentions do not permit unethical behavior. I daresay you would agree – we do not like marketing to be deceptive and to target vulnerable people. The State's public health messaging omits truths – like the potential harms of vaccinations – and the State not only targets vulnerable people, but makes them vulnerable by denying them access to their job and the market. This seems a step too far to me, even if it is ostensibly for the common good. Being righteous is quite distinct from being right – although the righteous will often fail to understand that distinction.

Dr Provax: I guess the State has made an assessment and determined it is better for society that people vaccinate. They have asked people to vaccinate as insurance. If you refuse the insurance, you’re on your own.

Dr Novax
: Well, let us return to the problem of adverse events from vaccination. They do happen as I think you’re prepared to admit even while you apparently condone the State’s effort to omit or hush-up such events because it might scare people. Informed consent is a part of virtually all medical practice whereby I must be informed, that is told about all the scary possible side-effects, and only then am I required to grant my consent. Vaccination seems to be a notable exception. The State wants to skip over the side-effects, and wants to over-ride consent.

Dr Provax: But side effects are just so incredibly rare.

Dr Novax:
I believe that they are, but what about the individual that does suffer an adverse event. Will the State compensate those who suffer? And even if they do, how will they compensate someone who dies? Australia has a dismal history of denying adverse events from vaccination, and has no compensation program for those that do suffer. 
Dr Provax: In fairness, the State has implemented a COVID-vaccination compensation program since about December 2021
Dr Novax: Yeah, I've seen that, but it vague on what is granted to the person who dies. And anyway, how much compensates for a death?

Dr Provax:
I hear you, but if you accept the statistics, then more people will survive if vaccinated than if unvaccinated.

Dr Novax:
I accept the statistics, even that more people will survive if vaccinated. But I resist the State’s right to restrict my freedom to choose medications for myself. I’m not insisting you do not vaccinate, I’m insisting on my right to choose for myself. You happen to have chosen vaccination, so of course it doesn’t bother you that the State insists that people be denied that choice. Ultimately, the State is asking me to buy their ticket in a lottery in which I do not wish to participate.
The Gamble
(to be continued!)

19 January 2022

Predicting the future imperfectly

Do humans want to know their future?

Yes, people are interested in knowing their future.

We want to know the future in terms of…

  •  what the weather will be tomorrow, and the day after, and the day after…?
  • whether our new product is likely to be a success in the market or not?
  • whether our large investment will be go up or go down in value?
  • what numbers will win next week’s lottery? 
  • whether or not we will survive the fatal disease we have contracted (with certainty, not a probability)?
  • can modern medicine prevent or cure the fatal disease I have contracted?
  • can we humans live forever?
  • do humans avert their own extinction?
  • what is the human-experience after death (assuming our quest for human-generated eternal life fails)?

Can humans know their future?

The future remains uncertain. No matter how good our prediction skills, the future is uncertain, both empirically and logically.

Empirically, even if we have “big data”, massive computing capacity, and fantastic skills, the weather tomorrow may be as predicted, but it may not. There is no certainty about what the future holds, and complexity and chaos theory ensures that it remains so.

Logically, even if the world is a series of causes and effects, there is no logic that permits us to say that many previous contingent events will occur again in the future (see Hume). Sure, the sun has ‘risen’ every day for thousands of millennia, but it does not logically follow that it will do so tomorrow. 

Even with “more data” and more skills, some of these questions about the future, especially the ones further down the list above, are likely to always remain beyond us.

What is the human-experience after death? Who knows? It has not stopped many people developing stories of what they think, even believe, or perhaps wish will happen after death. But the truth is we do not know. And even more, that we are unlikely to ever know.

Do humans avert their own extinction? We might desperately wish it to be so, but humanity does or does not survive remains in the future, and is unlikely to be known. The problem is open-ended for even if humanity survives the current apocalyptic scenarios, the possibility of extinction in some other, currently unseen and perhaps unknown apocalyptic scenario remains.

Can we live forever? It hasn’t happened yet although it is clear that human life has been massively extended beyond the standard “three score years and ten”. Can a human live forever? Perhaps, but perhaps not. Even if we do manage to insert our mental selves into a machine, what happens if the world ends and the machine stops? 

So many unknowns.

But there are also some confusions that get tangled with the idea of prediction.

The first is confusing possibility with prediction. It is possible that there is life after death, that humans escape extinction and that people get to live forever (or at least 200 years or more). So, yes, these outcomes might be possible, but that is not a prediction. The other outcome is also possible!

Which leads to the related issue of confusing guesses with predictions. Guessing that a tossed coin will come up heads is a guess, not a prediction. If the coin does come up heads, then it was a lucky guess, not a correct prediction. 

Predicting the future is already an uncertain game, but it seems certain that uncertainty will always plague questions about particular futures such as the human experience after death, whether humans avoid extinction, and whether humans can live forever. 

My prediction is that we will only ever be able to predict the future imperfectly.

- - - - - - - - - - - - - - - - - - -

"The history of predicting the future" (Rees 2021, Wired)

"Humans are bad at predicting futures that don't benefit them" (Beaton 2017, The Atlantic)

12 January 2022

Why is time so warped?

Time has a curious essence. Unlike the other three dimensions - length, breadth, depth - we can travel in only one direction through time: from past to future via the present.
We cannot visit a moment in time that we have passed.

Despite the past and future being simply two ends of one dimension, we take the past as cast in stone, and the future as unknown.

Travel into the past is impossible, travel into the future a dream.

How well do we ‘know’ our past & our future?

We fool ourselves that we ‘know’ both our past and our future with stories about each.

The story we tell ourselves about our past is called history.

We put a lot of faith into this story in some ways, but it seems unjustified. If history is important because it facilitates learning, how come our own history is full of stories that are like repeats on television where at some point, often much too late, we realize that we’ve seen this before?

The story we tell ourselves about the future is called a prediction. We put less faith into predictions in general, but curiously, we do put a lot of faith into some predictions. We have many imaginings about catastrophic futures – pandemic, climate change, nuclear war, etc.

All are quite possible, but we tend to focus on one at a time, a flavour of the month (or year). While the possibilities for global annihilation are plentiful, even infinite, annihilation by pandemic is the most current scare du jour.

Before death by pandemic was imagined, we feared annihilation by climate change. Before annihilation by climate change, we feared an ending in nuclear war. Before an end in nuclear war was imagined, we feared … and so on back to various doomsday scenarios, secular and religious.

05 January 2022

Outrage ain't right

“Reason is, and ought only to be, the slave of the passions”
  – David Hume, A Treatise of Human Nature (Book 3, Part 3, Section 3)


Enough of the outrage!

I hear your passion, your judgment, your indignation, your disgust. All because I'm unwilling to agree with you.

Outrage is easy to hear because it is pure passion speaking out. Loudly.

29 November 2021

Do you know what time it is ?

Claire asks Tiffany "Do know what time it is?"
Tiffany looks around at an old-fashioned clock sitting on the sideboard which shows that the time is 6.56. 

"Yeah, it is four minutes to 7," says Tiffany.
Following Tiffany's glance, Claire says, "Oh, that clock doesn't work. It always shows 6.56. So you are mistaken."
Tiffany looks at her mobile phone and says "Oh yeah, well my mobile phone says it is in fact 6.56 at the moment. So I was not mistaken, and I did know the time."
(Adapted from Bertrand Russell, Human Knowledge: Its scope and limits, 1948)

Does Tiffany have a legitimate claim to "knowing" the time after viewing the stopped clock? 
If the time was 6.56, and Tiffany believed it was, and justified that belief by reading the clock, does she have knowledge? 
The notion that knowledge is 'justified, true belief' suggests that she does. Perhaps we ought to change the definition of knowledge? How would you change the definition?


31 December 2020

Be who you are


Be who you are --
no-one else can be.

Become who you can --
no-one else can do.

(SSH 31dec20)


To be what we are,
and to become what we are capable of becoming,
is the only end of life.

Robert Louis Stevenson


Be who you are and say what you feel
because those who mind don't matter,
and those who matter don't mind.

Dr Seuss

31 October 2020

From impossible to improbable: small step or giant leap ?

Proposition: Neil Armstrong's walk on the moon is a hoax.
Impossible? Improbable? 
Is the difference a small step or a giant leap
Follow this cryptic journey from steps on the moon to the bowels of Christ fuelled by parsnips! 
Hang on tight!

Faith: The idea that moon landings are a hoax is simply ludicrous. They moon landings happened, the evidence is incontrovertible.

Skip: What is that evidence?

Faith: This article tells and shows how photographs taken by NASA's reconnaissance lunar orbiter reveal human footprints on the moon.

Skip: OK, but the photographs could be fakes. Or maybe NASA actually landed a mechanical lunar rover on the moon that has two wheels on each side with boots in place of tyre treads, and it was set to "walk" around a bit. Voila! Footprints.

Faith: Aww, come on, that's just stupid.

Skip: Stupid, yes. But possible?

Faith: No way. They have soil and rocks that they brought back from the moon that are not found anywhere on earth.

Skip: Well, that one's easy to challenge. The rocks are found on earth. They're in NASA labs. How can we be sure they are not elsewhere too? Absence of evidence is not evidence of absence. And besides, have you seen these rocks? Are you a geologist? Can you confirm that they absolutely cannot be of this earth?

Faith: No the experts have made this judgment. I trust the experts.

Skip: Sure, I trust experts too. But I also know that it is sometimes wise to ask for a second opinion. Experts do not always get it right, and often disagree. Indeed, it's almost certain that for any expert opinion, you will be able to find another expert who disagrees.

Faith: Oh this is silly. The theory that the moon landings are a hoax is simply impossible.
Skip: I'm not asking you to admit that there were no moon landings, or no humans walked on the moon, or even that they are a hoax. I'm asking you whether you might be wrong about man walking on the moon?

Faith: While I acknowledge the points you are making, they 'doth butter no parsnips with me' 😂

Skip: Let me respond to your 17th century idiom about buttered parsnips with a quote from the same century called Cromwell's rule: 'I beseech you, in the bowels of Christ, think it possible that you may be mistaken?'  
Faith: What?
Skip: Cromwell's rule says that anyone who is 100% adamant about their view is in trouble for two reasons: (a) they might be wrong and (b) they are blind to this possibility.
Faith: Ah, OK, I think I can see that. That the moon landings are a hoax is highly improbable rather than impossible. 
Skip: Yes, exactly. It's a small step with enormous implications.
Faith: But you have to make a giant leap to get over the remaining problem. Your view presents an absurdity, namely that the impossible is not possible at all? 😂 

Induction is the glory of Science, and the scandal of Philosophy
   -- C.D. Broad, Commemorative Address at The Bacon Tercentenary, (1926)

Words are but wind that do from men proceed;
None but Chamelions on bare Air can feed;
Great men large hopeful promises may utter;
But words did never Fish or Parsnips butter
   -- John Taylor, Epigrammes (1651)
 I never made a mistake in my life.
I thought I did once,
but I was wrong.
  -- attributed to Charles M. Schulz, creator of Peanuts