What is evidence?

Discussion in 'General Science & Technology' started by Ophiolite, May 10, 2016.

  1. danshawen Valued Senior Member

    I understood your premise just fine. You don't really accept much of anything as quality evidence. We already knew that, and it's not hard to figure out from your posts.

    Okay. So, would you mind gracing us (in this thread or in another one) with YOUR description of what constitutes quality in a proof, or does such a concept even exist in your world view?

    FYI, I don't have any pre-conceived notions about that either, so it is perfectly safe for you to take it in any direction you wish.

    Evidence definition (from the internet):
    the available body of facts or information indicating whether a belief or proposition is true or valid.
    synonyms:proof, confirmation, verification, substantiation, corroboration, affirmation, attestation Example: "they found evidence of his plotting"

    Oh, no. That can't be right. No mention of "reproducible" And what are these "facts?" Is everyone entitled to their own? Why can't they come from YouTube? My brain is melting again… How can "proof" also be "evidence?"

    The evidence seems to show, this thread not only doesn't belong here, but was unnecessary in the first place. How could anyone even get fired up about it? There were flame wars in the middle of it.

    No wonder the guy who started this thread is so hard to understand. Is he going to do this to every word definition he doesn't seem to get? The available evidence would seem to support it, and a few other hasty conclusions as well.

    I am not trolling this thread. This is a discussion. If I ever imagined that I wanted to troll you, I'd stop and go find something more productive to do with my time. What were you doing just before posting the OP?
    Last edited: May 22, 2016
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  3. Ophiolite Valued Senior Member

    Any members on this forum with a sound science/engineering education, whether acquired formally or by personal study, would share my distaste for the majority of things that might be considered evidence by those lacking training. I do not stand out from the scientifically literate crowd in that regard and I am proud that I do not. How about you?

    Proof is not a commonly used concept in science. I think you have been told that before. Please try to remember that in future. Consequently your definition that equates evidence and proof has no relevance to science. Proof is fine in legal situations, logic problems and mathematics. This is a science forum. I was making some points about evidence in the context of science. (That's why the frigging thread is in Science and Technology, not Philosophy.)

    Dan, I started this thread. I am not aware of any other members who are having difficulty understanding my points. Indeed, you claimed yourself that my premise was perfectly clear to you.

    Well, you claim you understood the premise yet now seem to believe - mistakenly - that I am having a problem with the definition of the word evidence. Open your frigging ears Dan - the problem I have is that some people, guilty of various forms of loose thinking, have a very bad grasp of what the word evidence means.

    And I am now more convinced than ever that something in your psyche means you have massive problems in understanding what you read. If you have the same difficulty with verbal comprehension, I wonder how often you get punched in pubs.
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  5. Yazata Valued Senior Member

    What hasn't really been addressed is the question that Ophiolite asked in the subject line: What is Evidence?

    As Jaegwon Kim is quoted as saying in the Stanford Encyclopedia of Philosophy:

    "In any event, the concept of evidence is inseparable from that of justification. When we talk about 'evidence' in an epistemological sense, we are talking about justification: one thing is evidence for another just in case the first tends to enhance the reasonableness or justification of the second."


    So the question that we are faced with is this: How does one 'thing' make another 'thing' more reasonable? It's not as simple as it sounds.

    Once we have the beginning of a handle on that, perhaps by elucidating the logic of evidenciary relationships in various real-life employments where evidence is relevant to conclusions, we can start to itemize the various kinds of things that can serve as evidence in different kinds of situations. (Personal experiences, others reports of their experiences, collective observations by groups, physical objects, experimental results, physical recordings, data sets, journal articles, mathematical proofs, logical inferences from any of these...) Only then can we try to make broad statements about evidence in general, and what is and isn't good evidence. I suspect that we will find that what is good evidence in certain circumstances might not be good evidence in others, so that there might not be any one-size-fits-all answer to this.

    'Evidence', whatever else it is, is the kind of thing that can make a difference to what one is justified in believing. Some people are convinced that what one is justified in believing is entirely determined by one's evidence. This view is often called evidentialism.

    The standard counterarguments to evidentialism are the problems associated with underdetermination. These refer to the fact that a body of evidence is typically going to be logically consistent with multiple conclusions. The most familiar of these problems is the problem of induction. Questions arising from the problems of scientific realism pose more difficulties: Does the evidence available to scientists justify belief in theories about entities that are in principle unobservable, like quarks, dark energy, cosmic strings or particular interpretations of quantum mechanics?

    More broadly, evidence and justification of belief is a subject around which all of the rest of our knowledge claims revolve. It's of fundamental importance in making sense of physics, of everyday life and in Sciforums' own incessant arguments about religion, scientism, "anti-science", ufos, ghosts and monsters. It's exceedingly important, anything but simple and it's already received a great deal of thought. (It's called epistemology.)

    Last edited: May 22, 2016
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  7. danshawen Valued Senior Member


    This is a book, not a paper. Here is a mini-review:

    "Written by two leading authorities on the subject, it presents a geochemical and geological survey of the crusts of the Moon, Mercury, Venus, Earth, Mars, the asteroid Vesta, and several satellites such as Europa, Ganymede, and Callisto."

    Perhaps the author meant "compelling evidence" or "proof" that the planet Venus displayed no evidence of plate tectonics in the sense observed on Earth.

    Did you also read this?:


    For plate tectonics to be EVIDENT in the crust of a planet, THE CRUST NEEDS TO REMAIN FRACTURED.

    So, Ophiolite, please tell us why you started this thread again? Axe to grind with one of the authors for some other reason, perhaps? It would be consistent. But I would find it more likely that you are simply inflexible with definitions, as the entire thread manifestly demonstrates.
  8. Ophiolite Valued Senior Member

    Dan, you do understand the meaning of the word "triggered", do you not? My posting of the thread was "triggered" by a specific paper. I have been so "triggered" many times in the past, but have - until now - not bothered to do anything about it on a forum. Thus that paper was an example of the practice that annoys me.

    Once again you go into silly detail about an example and completely miss the strategic point: a classic case of being unable to see the wood because you have knocked yourself unconscious on a single tree.

    You comment that "Perhaps the author meant "compelling evidence" or "proof". "
    Dan, my entire frigging point - which you claim to understand - is that the author should damn well have said so.

    (And as an almost off-topic aside, I can produce papers that provide evidence of plate tectonics on Venus. As it happens, on balance, I doubt that evidence, but it bloody well exists. That is the frigging point. Now please pay attention in future.)

    If you wish to know why I started the thread find a twelve year old and ask them to explain the OP to you.
  9. danshawen Valued Senior Member

    I do understand. Take care, Ophiolite.
  10. birch Valued Senior Member

    Aside from more practical uses of evidence, the problem with those who 'know' an event can happen or did and being able to prove can pose problems because not everything is repeatable depending on the variables that were involved that might be unlikely to occur again as in you cant artificially create every scenario.
  11. Yazata Valued Senior Member

    I agree. From my post #36:

    But like I said, while an emphasis on reproducibility and verifiability certainly helps in enhancing (not necessarily ensuring) objectivity, I don't want to cram the entire theory of knowledge into that little box. I can easily imagine real and objective events in the universe occurring on their own unpredictable schedule. Some astronomical phenomena might approximate that, where all we can do is keep watching the skies in hopes of observing another example of whatever it is. I can even imagine the possibility of totally one-off events occuring in the universe, whether products of unique one-time combinations of general physical laws or totally a-nomic events that conform to no general law of nature. The possibility of one-offs can't just be excluded a-priori. If repeatability and verification become part of how we define evidence, then the implication would be that there can never be any evidence for totally unique events.
  12. Kittamaru Never cruel nor cowardly... Staff Member

    And there are disciplines that deal with these situations exclusively - case in point, history. We accept, from historic accounts, that Napoleon Bonaparte, Marcus Aurelius, Cleopatra, etc all existed and made incredible marks on history, despite the fact that we cannot "go there" and verify them. This is mostly through written and, for a long period, verbal passage of history. These tales being further reinforced with archaeological findings and cultural influences.

    There are ways and methods to verify things that cannot be tested over and over... but so far, none of those methods have verified these stories.
  13. James R Just this guy, you know? Staff Member

    On the question of what constitutes evidence, I'm inclined to agree what Yazata posted above. A reasonable starting point is that something is evidence for something else if it tends to make that "something else" a more reasonable conclusion that it would otherwise have been. That is, evidence is supposed to provide a rational justification for a belief or conclusion.

    The general question of the circumstances under which we can say we know that something is the case is the subject of a whole branch of philosophy, namely epistemology. Evidence is a tricky thing to get a proper philosophical handle on.

    As has been demonstrated in this thread, another question which frequently arises is the quality of purported evidence for a conclusion. In that regard, I agree with Ophiolite's annoyance number 2, in which he points out that saying it would be nice if more people took care to replace "There is no evidence for X" by more accurate expressions such as "There is no good evidence for X" or "There is no convincing evidence for X" or "The purported evidence for X does not unequivocally compel us to accept X, and have you considered Y or Z instead?"

    Taking the UFO example as a case in point, the problem is clearly not lack of evidence. Magical Realist can provide us with endless poorly-shot videos and breathless "eyewitness accounts" of alien encounters. This is all evidence of a sort. But evidence of what? As Bells pointed out, the UFOlogists tend to start with piece-of-evidence A and then jump to conclusion E, while completely skipping the necessary steps B,C and D that require a sober evaluation of the strength of the evidence, its provenance, and other possible conclusions consistent with the evidence. This is not restricted to UFOs; it applies to virtually every kind of pseudoscience and, more generally, pseudo-scholarship.

    Pseudoscientists - at least the ones who aren't knowing frauds - are generally not educated in either critical thinking or in the scientific method. Therefore, they tend to be very poor at evaluating the quality of evidence. Science - unlike pseudoscience - is far more likely to subject claims to rigorous scrutiny. New claims in science are usually met with a healthy skepticism by the professionals in the field. Scientists are always on the lookout for errors in the work of other scientists, and in their own work, because if they don't weed out their own errors in thinking or evaluation then others will likely do it for them, sooner or later. Confirmation bias is always something to look out for. In pseudoscientific fields, confirmation bias is king. The UFOlogist wants so much to see alien spaceships that he will often go out of his way to ignore everything that doesn't scream alien spaceship! to him.

    Let's finish by looking at Magical Realist's summary of the evidence for alien spacecraft:
    I have some questions:

    Is there any actual evidence that any UFOs are "intelligently operated craft" controlled by non-human operators?

    How are claims of behaviours "beyond the technological capability of humans" tested by UFOlogists? It isn't enough to just watch an object in the sky and conclude that it is moving at hypersonic speed in ways that are technologically impossible. You have to know, for example, how far away the object is, how big it actually is, correctly identify it it the first place, and so on and so forth. You also need a good working knowledge of the technological capability of humans.

    Jets have been known to pursue the planet Venus. It's strange that no matter how fast they fly, they never quite manage to catch up with it. Or maybe not so strange.

    Lots of things register on radar, like rain clouds for example. What makes a particular radar blip unequivocally an alien spaceship?

    How do UFOlogists measure the "huge amounts of energy" emitted by UFOs? In what form is this energy emitted?

    Lots of things rarely make sound. High-flying jet aircraft often can't be heard from the ground, for example. Have all other soundless mundane objects been ruled out as possibilities?

    Similarly, lots of things can have physical effects on vegetation, like last time I ate some cereal. Likewise cars.

    Then there are all these "eyewitnesses" to close encounters with actual alien beings. How do we know these people are trustworthy? What if it turns out that some of them have been exposed as untrustworthy? Does that mean we can still trust all the rest until/unless they too are exposed? Do eyewitnesses ever make mistakes? Do people ever have dreams or hallucinations that seem real to them? I wonder.
    paddoboy and Russ_Watters like this.

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