How do you know that things are true?

Great Debates
1

OK, this is a bit of a weird one…

I was just reading a thread questioning the credibility of evolution, and it got me to thinking…

The vast majority of things I ‘know’ to be true are not the result of my own meticulous analysis, inspection and introspection. Okay, I understand the basics of evolution and how it works, but I don’t believe in it predominantly because of my understanding of the mechanics of it, rather I do because large numbers of people and institutions with whom I have placed my trust say that evolution is real. The same goes for the theory of relativity, the roundness of the earth and the names of most world capitals. If the dictionary, encyclopedia or reference book says it is so, then unless I have strong evidence to the contrary, I normally go along with it. So, when someone comes along and says “Evolution is bullshit”, my instinctive reaction is “It seems pretty logical to me; plus, a whole load of really clever people disagree with you - and I trust them more than you”.

Here is the crux of it, though. I know that what I know is true because of whom I trust. I trust academic and scientific consensus (when large numbers of academics and/or scientists get together and say “yup - this is happening”, that’s good enough for me). I trust most mainstream news media, albeit not completely unconditionally; when the BBC tells me that ‘War is happening in x country’, I tend to ‘believe’ it. Am I being intellectually lazy, or is it a necessary expediency to take things on trust in this way?

How do we know which sources are reliable and trustworthy? How can I, a person with very limited knowledge of quantum mechanics, ‘trust’ those who tell me about quantum tunneling?

2

Allow me to give you CARL SAGAN’S BALONEY DETECTION KIT. The whole book is well worth reading if this interests you.

In summary form, you can trust them the same way as you trust anybody else: by asking some basic questions about their neutrality and evaluating whether there is any way of checking their what they say.

Do they have a vested interest in your belief in what they say? Does your attitude towards quantum tunneling profit them financially? Does it advance their preferred political cause? If they don’t stand to profit from what they say, then they are probably trustworthy if you can ascertain…

Do they have any credibility amongst other experts. Expertise isn’t everything, but it counts for a lot. They may be able to bullshit *you *on the issue of quantum mechanics, but it’s going to be much harder to bullshit hundreds of people who have spent their life studying the subject. Which brings us to the third point…

Does the field have some means of evaluating ontological certainty. In simple terms, does the field have any way of distinguishing bullshit from knowledge? Science, for example, has a very rigorous way of doing this. Science is based on a few simple axioms, and any new claim has to proven consistent with those axioms before it accepted and it has to be proven consistent multiple times. The best science is also based upon the concept of falsifiability. There has to be some logical and achievlable manner way in which someone can collect evidence that would prove the idea wrong. That;s a very strong guard against bullshit because anyone at all can demolish the idea instantly.

Other fields, notoriously the arts, have no such mechanism. If someone says that an artwork is good, there si simply no way of gainsaying that. A mechanism for eliminating uncertainty doesn’t guarantee “truth”, but it does guarantee that the knowledge base can grow an still remain consistent an non-contradictory, which is one way of detecting bullshit.

And finally:

Is the knowledge consistent with reality? Reality is a tricky concept, but there are some aspects of reality that we all accept as being true: consensus reality. If knowledge is worth anything, it has to be consistent with that reality. That doesn’t mean it has to conform to our *prejudices *about reality, but it does have to conform to the way the real world is known to work. If someone makes a claim about quantum tunneling, then the consequences of that claim has to be detectable in the real world. If it can’t be detected in the real world, then it may not be bullshit, but the difference between the claim and bullshit is undetectable, so it may as well be bullshit. Or to put it another way, if we can’t detect any difference between a universe in which a claim is bullshit and the universe in which we live, then for all practical purposes the claim *is *bullshit. Whether it is true or not doesn’t matter, because in this universe it makes no difference, so we may as well assume that it is untrue.

In the case of quantum tunneling, you may not be *personally *able to determine whether it is detectable, but that is when you go back to the earlier points and evaluate the credibilty of the people who have tried to detect the consequences.

There is never going to be a foolproof way to know whether to trust anybody about anything. The very nature of truth is ambiguous and impossible to determine. But what you an do is evaluate whether what some says is prone to bias and whether it is consistent with the reality that you choose to apply it to.

3

There may be such a thing as capital T Truth, but in most cases where truth is in dispute, what it boils down to is: which proposition is truer. And then I use the tools that Blake mentioned, or trust that someone somewhere has done so. There are a lot of someones out there, so that’s not a dumb assumption.

4

You can’t verify everything: Even if you had the ability (and no single human does), you wouldn’t have the time. There are a couple of things you can do, though. You can verify selected things, and you can look for consensus. For instance, I trust Cecil Adams to give good answers. Why? Because on some topics I’m able to verify what he says, and on other topics, even though I lack the expertise to verify him myself, those who have that expertise agree with him. How do I know they have expertise? Because there are a bunch of them, and they all agree with each other on most points of those topics, and those few points of theirs that I have the ability to check personally all work out.

5

Fascinating.

I like the idea of a “world view”, an integrated set of expectations that derives from our own experiences and thoughts and from what others say.

I have read enough about evolution to think that it just has to be true, and I see total consensus from people who I think should know. At this point I don’t think I can even say whether it is my own understanding of the mechanism or the consensus I hear that is more important to me.

My world view also includes various things relating to the existence of extraterrestrial life, but in that case there are various doubts. I think there must be an infinite number of extraterrestrial civilizations that have already passed us, but enough of the details are shaky that I don’t feel complete confidence. So, it’s OK to have incompletely formed world views. It’s just that evolution has gone way beyond that for me and, I think, any other reasonable observer.

6

WRT how the universe works:

  1. Decide how you know things are. Most of us decide to trust our sensory input.
  2. Decide what true is. Most of us decide something is true if it has accurate predictive value.
  3. Decide how to determine that. Most of us accept a scientific method.
  4. Decide to what extent an assertion has been subjected to the scientific method.
7

Verifiability is important even if, as a practical matter, you’re not going to actually verify the claim yourself. The fact that a person is willing to explain how a claim can be verified means he thinks his claim would stand up to that test. And while you may not choose to take up the challenge and repeat the experiment, other people do and they can report their results.

Quackery and pseudoscience aren’t verifiable. They’ll come up with elaborate reasons to explain why you have to take their claims on faith and can’t test them.

Here’s a prosaic example of how this works. Let’s say we’re talking and I casually mention I’m dating a Sports Illustrated swimsuit model. But I tell you she’s off on a modeling job in South America and the magazine doesn’t let her answer phone calls. So you just have to trust me on this.

Now, let’s say we’re having the same conversation and I casually mention I’m dating a Sports Illustrated swimsuit model. But this time I tell you she lives a few blocks away and ask you if you want to go over to her house so I can introduce you to her.

Even if you don’t want to go over to her house, you’re probably going to believe me in the latter conversation because I was willing to take you there if you wanted to go.

8

In general, the people that tell you about science you can trust will be amongst the same community of people who have proven it to work by employing it in one way or another - for example:
The people who tell you evolution is true are part of the same community of people who have used evolutionary theory to make useful predictions about immunity, biodiversity, adaptive resistance, etc.
The people who tell you the Earth is many millions of years old are part of the same community of people who know where to find the oil, who know why earthquakes happen, etc.
The people who tell you about quantum tunneling are part of the same community of people that make working electronic devices such as transistors and LEDs.

The people telling you other stuff are not in the business of biology, geology, technology - they’re in the business of convincing you their story is true.

9

In this thread, some means to increase the odds of having a reasonable opinion are noted, and I agree with them.

But the answer to your question is: You don’t.

I feel that I know enough statistics that I can have a reasonable opinion if I read extensively on a subject. But it takes so long that I can only study a scientific issue, for myself, maybe once every few years. I did it once for blood pressure medicine, and made a case for changing meds to my Ivy League Summa Cum Laude family med doc. He said that he’d heard top blood pressure experts sarcastically tear into each other regarding the studies and results I was reading about, and didn’t know who was right. So he was fine with doing what I asked :slight_smile:

Except for those few issues I have truly studied in depth, for everything else I have to use rubrics, such as that mainstream medicine beats alternative medicine, and the Berkeley evolution profs probably have a better handle on the subject than the creation studies guys at Liberty University.

I’ve gone on some fossil collecting outings with one of our sons. But have I actually spent enough time looking at the fossil record to reach independent conclusions? No, I’m relying on the probability that the mainstream research scientists are more or less correct.

10

Chiropractic is verifiable. And a lot of studies, which I have not read, attempt to do so.

Now, even though I can’t tell you what is wrong with the studies that that support it, I still have an opinion that chiropractic is quackery.

One problem with alternative medicine is that chiropractic professsors would rather see what they do today verified than find something better. Mainstream medicine, going from one scientific revolution to another, improves over time. Chiropractic is stuck with manipulations that maybe, possibly, in 1900, were better than alternatives then available, but are less and less likely, with each passing year, to be the best treatment available.

Evolution is a little like that also. Genesis isn’t getting any better. But as top scientists get tenure by overcoming Darwin’s weaknesses, mainstream evolutionary theory becomes a closer match to the evidence.

11

When you read about how the scientific community works, you can see that it does things in a way which are likely to zero in on verifiable truths. When you read about how the religious community works, you can see that it does things which are not likely to zero in on verifiable truths. If it’s verifiable truths you’re after, then, the judgment of the scientific community is what you want to go with.

12

Right, one can not know at the beginning, but tools like the internet, if used properly, can get you a lot of information regarding how to go about on identifying good sources from the bad ones.

The basic tip? Always ask the one telling you to believe in something: “How do you know?” or like Science and media Writer Peter Hadfield says: “What is your source?”

In the following short video one good example comes when a reporter friend of Hadfield send him a Daily Mail report on why planet Mars was red, telling the readers that one scientist discovered that there was an ancient nuclear reactor or explosion that destroyed the planed and the red radioactive material from the explosion covered the planet.

The main point of this fairly easy to do exercise is then apparent, one does not need to look at scientific reports yet, the simple effort of looking at the original cite and for the sources they used many times exposes right away the huge flaws that any non expert can identify.

In the Mars case, the Daily Mail mention the source as Dr. John Brandenburg in an interview in FOX news. (Many who already are aware of this system are already rolling their eyes at the sources already found here, but one has to continue to be sure) Hadfield then Googled the name and FOX News together and got the interview from FOX news, **and then it was clear that the Dr. was only giving his opinion, there was no study cited, nor any experiments that the Dr. used for his claims.
**
That should be enough for dismissing FOX and the Mail as unreliable sources, (also that they did not told the reader that the Dr. was not an expert in planetary geology or planetary physics) but if one wants to look deeper, it is also not that hard with the technology of today.

Hadfied then looked at the papers published by Brandenburg and found one, where he did write about the ancient **natural **reactor that possibly blew up on mars, but the paper was not a peer reviewed one, it was just one of hundreds of papers submitted in because of an open invitation for matters to discuss in a planetary conference, that is, papers that are speculative and would rise and fall quickly once the conference took place, as the following publications showed, that idea of the ancient reactor blowing up on mars is conspicuously missing from references in newer peer reviewed papers and academic discussions, IOW, that original paper from Brandenburg was for sure laughed at.

Unfortunately it is clear that that an active dismissal of a ridiculous paper is something that does not get on the way for a good history from FOX, nor it was the conflict of interest the Dr. had in pimping a book (with less sources) on a possible ancient alien civilization on mars raised any flags at the Daily Mail.

Bottom line is that scientific papers tell you that Mars is reddish because of oxidation, not for a past nuclear explosion.

The take home advise is what polls guru Nate Silver does, clean your sources, dismiss the bad ones, even from the ones that you would think are closest to you ideologically.

http://www.fivethirtyeight.com/2010/06/research-2000-issues-cease-desist.html

When you clean up your sources of information, the less work, wasted time you will do. And the less one will look like a dunce if one posts items like that Mars piece in places like the Dope and the OP continues to defend it after others post the good information that it is now fairly easy to find nowadays.

13

A lot of creationist or ID advocates claim that there is no difference between faith in science and faith in the Bible, but they’re wrong.

For one thing, if you’re in a dark room, and you flip the light switch, the room lights up. If you pray for light, the room remains dark, even though Jesus said that if you have faith, you will get whatever you pray for.

But that’s not the most fundamental difference. The most fundamental difference is, you can verify what science says for yourself.

If it’s something complex, like subatomic physics, and you have no formal education, then it might take you 10 or 20 years to acquire a PhD in physics and become an expert on whatever it is you wanted to know about subatomic processes, but in principle, it can be done.

You can’t do that with religion. You can study your whole life, but all you will get for it is an increasingly sophisticated understanding of what the author(s) of the scriptures believed. But you won’t learn anything verifiable about life after death, or what God thinks about gay marriage. You just have to accept what someone else, often someone you know very little about, said about those subjects.

14

One way to bullshit detect is listen to how the researchers/scientists talk about their discoveries. News reports will always oversell the results, but when the scientists say things like, “This will lead to interesting new research,” or, “More work needs to be done,” you can usually trust them. Science is incremental, not finite or absolute.

If you hear, “This prooves…” or, “…shows conclusively,” or the like, be wary. If they’re selling something, it’s bullshit. If the story is written before or without a published journal article, be doubtful. Wait for an independent repeat of the results, too (remember faster then light particles?).

Remember Karl Popper’s falsifiability doctrine. All theories are not proven, just waiting to be proved false. Gravity, evolution, and general relativity have stood up against repeated tests of falsifiability. If minor tweaks are needed, that doesn’t mean the whole thing is false, either.

15

Well, really, maybe nothing you experience or absorb is real. Maybe everything, including this post, is some kind of last minute death-dream before you’re run over by a bus or something.

There comes a point where you trust stuff like a track record, education, consensus by a large number of equally qualified findings in the same field, and so on.

16

Also, some subatomic experiments, like the Rutherford “gold foil” experiment, actually could be repeated by nearly any one of us here. The equipment isn’t all that sophisticated, and actually isn’t that expensive either. (A very little gold makes a pretty big amount of gold foil.)

An amateur scientist really can, with little effort and not a lot of money, duplicate many of the foundational experiments of modern science.

17

To start with, not everything you know is true.

For example, our understanding of science is always evolving, and there is no doubt in anyone’s mind that, for example, a lot of today’s medicine is going to look pretty crude in a few decade’s time. But, it’s pretty much the best we’ve got. Likewise, a lot of news reporting is somewhat off, and even sometimes outright wrong. I remember a few years back there was a famine in Somalia, but definitely not in Eritrea (which experiences different weather patterns.) Nevertheless, you can find quite a few articles from very good sources about the “famine” in Eritrea. And then there are things that have no real truth. There is no one and only true name for the world’s capitals. There really is only what everyone agrees on.

So yeah, a reasonable chunk of what you know may not be entirely accurate. But it comes down to what you are using the information for. If you are an engineer, I would hope that you do have a strong understanding of engineering, and have done the proofs and whatever that underpin the discipline. But if you just want to talk about buildings, chances are what has filtered up through general knowledge is good enough to do that with.

18

Good question.

About 10 years ago, many people were telling us that Saddam Hussein had plenty of chemical and biological weapons and was working to obtain nuclear weapons as well. By common standards, the claims they were making appeared quite trustworthy.

[ul]Vested interests? We could argue that GWB and other politicians had financial links to companies that intended to profit from the Iraq War, thus giving them a motivation to lie. But pro-war arguments based on the WMDs also came from newspapers and other sources that weren’t going to profit from it.[/ul]
[ul]Expertise? Plenty of people with credentials in foreign pollicy and other relevant fields told us they were sure about Saddam’s WMDs.[/ul]
[ul]Verifiable evidence? They stood there and showed us pictures, documents, reports, and so forth which supposedly proved that what they were saying about Saddam and his WMDs was true.[/ul]
[ul]Consistent with reality? For those of us living in the USA (or anywhere but Iraq) it could all seem consistent with what we did know about Saddam. He had used chemical weapons in the past, and stockpiling them would seem generally consistent with what murderous dictators did.[/ul]

So the bottom line seems to be that by common standards, an ordinary person at the time should have judged the claims about Saddam’s WMDs to be true, and yet they actually were false.

19

Not a very fair example, as it was dealing with an alleged body of evidence that was not independently verifiable.

Also, (you were already a member here at that time?) I seem to recall that the ordinary people of the SDMB, by and large, judged the claims false.

20

In the early 2000’s I also wondered how people I knew who seemed intelligent and (otherwise) well-informed could disbelieve evolution, so I looked into the question, both online and reading a dozen or two books on both sides of the question.

I found that, in general, the anti-evolution crowd:

  1. had an agenda (sometimes a bit hidden, but the money usually came from one creationist source)

  2. tended to have contradictory theories: there was no big anti-evolution consensus. On the contrary, an argument used to discredit one fact was incosistent with someone else’s argument to discredit another fact.

  3. did not have a plausible testable theory to replace evolution (other than “god of the gaps”)

Furthermore, the logic, science, and evidence of evolution is mostly understandable by an educated layman (meaning me).

More recently I tried the same analysis of climate science. It quickly became clear that I could not understand the science without some very serious study plus a far better understanding of statistics. It was pretty dense science. But I found the same three points mentioned above.

We can’t treat scientific results as incontrovertible truth; we have to take them as the best understanding that we have at present. As mentioned in posts above, most scientific theories are heavily used to obtain practical results, and this includes the theory of evolution. (Not so much climate science, at least, yet.)

When a theory is accepted by all the world’s major scientific organizations, we can take them as the concensus. The concensus may be incorrect, but from a practical standpoint, the burden of proof is on those who object.

When I looked into this a few years ago, the best I could find was that chiropractics had comparable results with theraputic massage. Results like this don’t go very far to verify chiropractic theory.