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I've heard many scientists claim that science is not based upon assumptions we believe are true, but upon factual truths found empirically via the scientific method.

For example, they claim the fact that light travels at a definite speed in a vacuum (the same in all inertial frames of reference) is "true". But how do you actually prove that something is true beyond being a true proposition in all experiments performed about the speed of light?

Is this not having the whole thing backwards? I expect that if the speed of light is indeed finite and invariant, and this is a truth that goes beyond any experiment, then I'm going to find that the speed of light is invariant in any experiment. I should not, however, infer that there is an absolute truth because I can confirm a statement is true in a finite number of experiments.

If light always travels at c in a vacuum, I can confirm it in my experiment. A positive truth value of the implication should not be able to tell anything about the sufficient statement, unless we are able to prove that the sufficient is true also whenever the implication is true (which would turn the statement into an "if and only if" type of proposition).

One could say the exact same about Newtonian mechanics. They are not said to be "true" anymore, at least not with the same frequency I hear the statement about the speed of light is true.

So, can a scientific theory (for example, Special Relativity) be proven true? Or can it only be proven false? And as always, do my own claims and questions make sense at all?

Niki Di Giano
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    Possible duplicate of [Is Science about Truth or Adequate Models?](https://philosophy.stackexchange.com/questions/442/is-science-about-truth-or-adequate-models) – Conifold Aug 22 '18 at 21:27
  • [Why should science be falsifiable?](https://philosophy.stackexchange.com/questions/25350/why-should-science-be-falsifiable/25354#25354) is another duplicate. This issue is also not specific to science and depends on definition of "prove". Strictly speaking, we can not even prove that the Sun will rise tomorrow. We can only be confident to various degrees and the possibility of being wrong is always there, with anything. – Conifold Aug 22 '18 at 21:33
  • What value do you ascribe to "truth"? What theory of truth do you presuppose? In pragmatic sense a scientific theory indeed can be true. And it seems to me that *confirmed* science in itself having pragmatic value should be called pragmatically true as it serves its function. – rus9384 Aug 22 '18 at 23:05
  • I am just a beginner in the field of philosophy in general, let alone epistemology. In my mind, the word "truth" means something that is always, under any circumstance, verified about the universe (even if there's nobody to perceive such a thing). For example, "either it's raining or it is not", as much as being a tautology, it is such a truth. The statement "given Zorn's lemma, the well-ordering theorem follows" is also true in this sense (yes, that might lead us down a dark alley) because the two are equivalent things. – Niki Di Giano Aug 22 '18 at 23:32
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    This question is just the question of scientific realism isn't it? At least replacing "prove" with the more liberal "justify". Scientific realists claim that our best theories are true, and that we are justified in thinking so (by induction and abduction), while anti-realists don't make this claim. – Quentin Ruyant Aug 23 '18 at 07:22
  • its called the "scientific method" or "scientific methodology" try searching on that in this forum. The question has been beaten to death. – Swami Vishwananda Aug 24 '18 at 09:07

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What it means for a scientific theory to be "proven" is different from what it means for a mathematical theorem to be proven. Indeed, for any scientific theory, we can never be 100% sure that there aren't somehow some unusual conditions under which it is not accurate, and under which we have done no experiments yet. This was the case for Newtonian mechanics. Of course, we can become extremely confident that the theory will make accurate predictions, at least under certain conditions. This link ("Scientific Proof Is A Myth") has more discussion.

present
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  • I could only accept one answer, but I had a hard time choosing between yours and Flo's. – Niki Di Giano Aug 23 '18 at 09:42
  • More precisely, the problem is not that the theory is wrong. It is rather than the theory relies on assumptions which are wrong. In a world where such assumptions hold, the theory would of course be correct. – luchonacho Jan 16 '19 at 16:00
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Can you prove a scientific theory is true?

No, you cannot. Scientific theories generally provide some sort of generalized description of observed related phenomena. The theory of General Relativity for example delivers an excellent (as in amazingly accurate) mathematical description of how gravity works (outside of the quantum scale), which has corretly predicted a large number of astronomical observations and which can explain a lot of observed phenomena.

However, since we can only make a finite amount of observations, we must assume that there may be circumstances in which the theory does not hold.

The conclusion would then be that while we cannot ultimately prove General Relativity to be true, we can (in principle) prove it to be false by discovering a reproducible effect that contradicts GRs predictions.

The point I am trying to make here was made first by Karl Popper[1], whose works "The Logic of Scientific Discovery"[2] and "Conjectures and Refutations" are the cornerstones of what is called "Critical Rationalism"[3].

[1]https://en.wikipedia.org/wiki/Karl_Popper#Falsifiability/problem_of_demarcation [2]https://en.wikipedia.org/wiki/The_Logic_of_Scientific_Discovery [3]https://en.wikipedia.org/wiki/Critical_rationalism

Apologies for just linking to wikipedia. I'm sure there are better sources out there, but the wiki articles, in particular the 3rd one, should at least give you a rough idea about what I mean.

Flo
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Yes you can.

"I should not, however, infer that there is an absolute truth because I can confirm a statement is true in a finite number of experiments."

This "absolute truth" is irrelevant because reality is inductive. There is no "absolute" perception that humans have so it's not misleading to call something as truth when we used the strongest form of reasoning that we use for every other aspect of our lives. The quality of this truth based on the number of observations is a different topic though.

Cell
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  • In the absence of a perception of absolute truth, how do we know that a scientific law is proven? – David Thornley Aug 22 '18 at 18:07
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    Would you deny absolute truths exist such as all triangles have 3 sides? We can distinguish temporal truths and permanent truths. So the point the OP seems to Express is why is truth used in an absolute sense when scientist really mean temporal truths. If you mean temporal truths then Express that publicly. Some truths are subjective and those are temporal. – Logikal Aug 22 '18 at 18:42
  • @Logikal “all triangles have three sides” is a case of circular reasoning, since a triangle is defined to have three sides. Are there any (probably) absolute truths that are not circular? – 11684 Aug 22 '18 at 21:12
  • @David Thornley probably in the same way that I can predict your mind will have no uncertainty of your immediate death if I offer you a cup of methylmercury, cyanide, or methanol despite a test has never and will likely never be conducted given your exact body composition. So unless you are curious in having a sip then we can agree that you think chemistry principles from theory and expeirment are proven. – Cell Aug 22 '18 at 21:16
  • @Logikal No I don't deny the absolute truth that triangles have 3 sides, but triangles don't exist so it's not relevant here. – Cell Aug 22 '18 at 21:18
  • @11684, there are other absolute truths that are sense verifiable such as all women are human beings. You can't have one property of being a woman and be some other life form than a human being. There are humans that are not women which is also an absolute. These claims are not subjective. – Logikal Aug 22 '18 at 22:17
  • @cell, what do you mean triangles dont exist? Even Fischer price makes blocks for kids in various shapes including the triangle. Egyptian pyramids are models from triangles as each face side has exactly three sides and three points of reference . Even outside of semantics can something be a dog and not an animal? This is neccessary. – Logikal Aug 22 '18 at 22:22
  • @Cell I don't have to think the principles to be proven. If, for example, I think there's a one in a trillion chance that they're wrong and I'll survive poison, I'm not going to try it, and that attitude means I don't consider the matter proven. (Rasputin's murderer claimed he poisoned Rasputin with cyanide to no effect, although the autopsy found no sign of it.) – David Thornley Aug 22 '18 at 23:04
  • @Logikal I can find you plenty of science fiction that has creatures generally considered and called "women" who aren't human. Either you define a woman as a female human being, in which case we're talking about semantics and not science, or you have to concede that we might find creatures we consider women who aren't human. – David Thornley Aug 22 '18 at 23:06
  • @Davidthornley, biologically women can be distinguished from other human beings like males and every other species. You can't match a woman biological signs and the life form is not a human being. Even scifi movies such Men in black have aliens disguised as human but their true identities are hidden. – Logikal Aug 22 '18 at 23:47
  • @David Thornley You just showed my point though. If you decide against performing an action based on the evidence because you think the likelihood of being wrong is so small then you have been convinced of the proof. Proof isn't absolute in science or life in general it just has to be convincing to a reasonable person like in law. – Cell Aug 22 '18 at 23:56
  • @Logikal Then you _define_ “woman” as human, in which case your example “all women are human”, again, is circular reasoning. “Not all humans are women” is also circular, because you define “woman” as a subtype of “human”, so without any empirical evidence we can already claim “not all humans are women”. – 11684 Aug 23 '18 at 08:25
  • @11684, I did not define woman semantically but stated biologically the makeup of a woman can be distinguished from other life forms even without a human claim being used. I did not use the word being defined with a term in question. If I were to do that then that would be circular. What you mean to say is some words are defined semantically not use circular reasoning. Mathematics does similar things with theorems do you complain there too? – Logikal Aug 23 '18 at 12:05
  • @Cell The OP seemed to want something more than empirical proof, wanting more to support the speed of light beside being confirmed by every test we've done. Is Special Relativity right, or is it just a better approximation than Newtonian mechanics? No amount of experiments and observations can guarantee it. – David Thornley Aug 23 '18 at 20:08
  • @Logikal So, how do you define "woman" and how do you define "human"? We're descended from creatures that are definitely not human and whose females were definitely not women. Did the transition to "human" and "woman" happen simultaneously, and, if so, why? Could there have been females in that chain that are women but aren't human? – David Thornley Aug 23 '18 at 20:13
  • @David thorneley, how I define the terms doesn't matter. How a biologists distinguish the types of animals & species matters. The point is they can be distinguished. How about a snake that is not a reptile if the human. And woman example is not clear. Can x be a snake and not a reptile simultaneously? You seem to be not picking and reaching for anything . How do you know we are descended from creatures but not know of any absolute facts? The term woman goes with a specific species and not just the attribute of being a female. A lioness is a female lion for instance. – Logikal Aug 23 '18 at 20:21