I've asked the people who have made these statements to explain why they're true but I don't get any satisfactory answers. Can someone explain why unfalsifiability is required for something to be true or knowable? — Hallucinogen

To be clear, falsifiable means, "I can imagine a situation in which something is false."

Let me give you an example.

John is a human. If John were a snail, he would not be a human.

Here is something unfalsifiable.

A unicorn is a magical creature that cannot be sensed in any way.

What state of reality could falsify the unicorn?

Is there a scenario we could imagine where the unicorn does not exist? "No, that's impossible because we can't sense it. We just know it exists." Or if the unicorn did not exist, there would be no state change elsewhere. There is no situation that is different in which the unicorn exists, and not.

Now more specific.

"The loch ness monster exists."
But no one has ever recorded it. "It doesn't matter, its very stealthy so that's why we haven't found it yet."

Is there any observation or research that we could do where we don't find the loch ness monster where we could claim it doesn't exist? "No". Thus the loch ness monster is not falsifiable. It is a belief system that asserts its truth as a matter of necessity, and no amount of evidence or thought could negate its assertion of existence.

To be clear, falsifiable means, "I can imagine a situation in which something is false." — Philosophim

You have to make it clear that the "situation" is empirical. Imagining that a contradiction appear in front of you doesn't work because a contradiction undermines the consistency we rely on for error-checking. Logical impossibility needs to remain intact for us to be able to decide whether something is being falsified or not.

Here is something unfalsifiable.
A unicorn is a magical creature that cannot be sensed in any way. — Philosophim

True.

But there's statements that we know to be true without sensing something or recording something, so the inference doesn't appear to be valid.

To be clear, falsifiable means, "I can imagine a situation in which something is false."
— Philosophim

You have to make it clear that the "situation" is empirical. — Hallucinogen

I should probably say "Testable". That normally is empirical, but it there was a non-empirical way of testing something, its the testing that matters.

But there's statements that we know to be true without sensing something or recording something, so the inference doesn't appear to be valid. — Hallucinogen

Knowing something is true doesn't mean its falsifiable. John is a human. We know this. Its true. But if he were a snail, he wouldn't be a human. Falsifiable does not mean, "It can be proven to be false", its that "There is a state of being which would negate the claim that "X is Y", and that can be as simple as "X cannot be Y if X is Z".

Falsifiable does not mean, "It can be proven to be false", its that "There is a state of being which would negate the claim that "X is Y", and that can be as simple as "X cannot be Y if X is Z". — Philosophim

:up: I think Hallucinogen's dissatisfaction comes from wanting a definitive call on whether or not all statements have this available. They don't. But ones which are apt for it either have what you've described (i.e an counterfactual) or they don't.

There's a claim I've come across numerous times, to the effect of "If P is unfalsifiable, then it cannot be known to be true or false". — Hallucinogen

That claim seems to be based on a misapplication of Popper's Principle (or rule of thumb) of Falsifiability*1. Karl Popper concluded that humans --- based on limited information, from a relative perspective --- can never know or prove Absolute Truth. Consequently, Scientific "facts" remain tentative & conjectural, but more-or-less useful & practical. And philosophical "truths" are posited, not proven. So they remain moot after all these years. Moreover, (Bayesian) degrees-of-belief are Probabilistic (statistical), not Absolute (incontrovertible).

The current issue of Philosophy Now magazine has a letter-to-the-editor, on the topic of "limits of knowledge". One writer said "originally, I thought everyone agreed that knowledge and truth were not relative, but absolute". And indeed, the ancient Greek philosophers aspired to Ideal truths*2. But in retrospect, their universal principles were inferred generalities, not specific observed facts. So, the writer noted that "absolute truth is much like infinity : mathematicians and particle physicists love the concept, yet no one can touch it. . . . . But just because you can't find it, does not make it false. Popper be damned : keep looking."

Therefore, when someone claims to possess slam-dunk, mic-drop Truth, it's usually based on some personally accepted authority, like the Bible. So, you'd do better to falsify (critical analysis) the authoritative Source, than to analyze the specific Truth (dogma). :smile:


*1. Karl Popper's concept of falsifiability is a principle in the philosophy of science that defines a theory as genuinely scientific only if it can be proven false (falsified) through observation or experiment, distinguishing science from pseudoscience like astrology or psychoanalysis. Instead of trying to verify theories (which is difficult), scientists should actively try to disprove them; a theory gains strength by resisting falsification, not by being confirmed. This critical approach, known as falsificationism, posits that science progresses by eliminating erroneous theories, not by proving them absolutely true, using logical deduction to reject hypotheses that contradict predictions.
https://www.google.com/search?client=firefox-b-1-d&q=karl+popper+falsifiable

*2. Greek philosophy holds that absolute truth is an unchanging, objective, and universal reality existing independent of human opinion, often discoverable through reason, logic, and contemplation. Key proponents like Socrates, Plato, and Aristotle argued against relativism, focusing on absolute moral truths, the Theory of Forms, and objective, eternal knowledge
https://www.google.com/search?client=firefox-b-1-d&q=greek+philosophy+absolute+truth
Note --- Plato abhorred the pragmatic truths of practical Sophistry, in favor of Logical & Ideal Truths. So, he would be appalled at Einstein's Theory of Relativity (frames of reference).

But this is flawed because of tautology, — Hallucinogen

Isn't tautology always true in logic? Tautology is not flawed.

"If it’s unfalsifiable you don’t know if it is true or false." — Hallucinogen

But how do you know if it is unfalsifiable first place?

Since theories are usually ambiguous and interpreted within a specific context, I would say:

A theory's interpretation is unfalsifiable if the interpretation does not imply a means for potentially refuting the theory under that intepretation.

For example, we can probably all agree that "All Swans are White" is a falsifiable proposition; I say "probably" because I am assuming we can all agree that a "swan" isn't white de dicto but de re, and that we can all agree that whiteness is a publicly observable and testable empirical category.

On the other hand, if either of those two assumptions fail, such that the theory is no longer interpreted as implying a means of potential refutation, then the interpretation of that theory is unfalsifiable.

Isn't tautology always true in logic? Tautology is not flawed. — Corvus

I didn't say tautology is flawed.

But how do you know if it is unfalsifiable first place? — Corvus

A statement is falsifiable if we can specify a condition under which empirical observation can contradict it.

The question isn't what un/falsifiabiliy is, the question is why would someone think that if X is unfalsifiable, then there's no way to determine if it is true or false.

A statement is falsifiable if we can specify a condition under which empirical observation can contradict it. — Hallucinogen

Could you give some example cases? Because it seems depends on what the statements were.

Any scientific statement, for example: "All swans are white".

Any scientific statement, for example: "All swans are white". — Hallucinogen

Just means that all swans seen up to now are white. If you spotted a black swan tomorrow, that doesn't negate the statement all swans are white. The black swan should be treated as a rare case, which needs further investigation on its nature.

Just means that all swans seen up to now are white. — Corvus

What do you think I was trying to say?

If you spotted a black swan tomorrow, that doesn't negate the statement all swans are white. — Corvus

I'm starting to get the impression that you're joking.

Nuh. Swans are black. The white ones are foreigners.

I'm starting to get the impression that you're joking. — Hallucinogen

No joking. Common sense.

but it there was a non-empirical way of testing something, its the testing that matters. — Philosophim

No, because including tests that have to violate logic to return a false answer simply gets rid of all meaningful-but-unfalsifiable statements. All you're left with is paradoxes and unintelligible statements. Unfalsifiably true statements like tautologies are an important category.

Sure. It's common sense that seeing a black swan doesn't negate that all swans are white.

The critical words you seem to miss here is "up to now".
Don't forget the statement was made based on the past event, not now or future.

The critical words you seem to miss here is "up to now". — Corvus

This is what you said, look.

If you spotted a black swan tomorrow, that doesn't negate the statement all swans are white. — Corvus

The "up to now" is in contrast with the statement you're making. So it doesn't save it from being logically fallacious.

The "up to now" is in contrast with the statement you're making. So it doesn't save it from being logically fallacious. — Hallucinogen

The statement All swans are white is based on the past observations, hence it doesn't say anything about now or future observations. If it does, then it would have been a prediction, not a scientific statement.

There's a claim I've come across numerous times, to the effect of "If P is unfalsifiable, then it cannot be known to be true or false".
There's been a few ways I've heard/seen it worded:
"If it is unfalsifiable, it cannot have evidential warrant for its belief",
"If it’s unfalsifiable, there’s no reason to believe it."
"Something that is unfalsifiable could be true, but there's no way for us to be able to conclusively determine that",
"If it’s unfalsifiable you don’t know if it is true or false." — Hallucinogen

These are not all equivalent. The statement that I bolded above is correct: "If it is unfalsifiable, it cannot have evidential warrant for its belief." The operative words here are evidential warrant. Here are some examples of beliefs that do not derive their warrant from evidential support, but may still be truth-apt (there is controversy about the last one):

• Bachelors are unmarried
• 2 + 2 = 4
• The bishop moves along diagonals
• I am cold
• Stealing is wrong

Now, what about falsifiability and evidential warrant? This is a narrower question about whether there can be a proposition that can be confirmed by evidence but not disproved by it. The general agreement, expressed by the statement cited above, is that that should not be possible. If evidence cannot move your belief in one direction, it should not be able to move it in the opposite direction either. Contrary cases are indicative of confirmation bias.

Falsification was first developed by Karl Popper in the 1930s. Popper noticed that two types of statements are of particular value to scientists. The first are statements of observations, such as 'this is a white swan'. Logicians call these statements singular existential statements, since they assert the existence of some particular thing. They can be parsed in the form: there is an x which is a swan and is white.

The second type of statement of interest to scientists categorizes all instances of something, for example 'all swans are white'. Logicians call these statements universal. They are usually parsed in the form for all x, if x is a swan then x is white.

Scientific laws are commonly supposed to be of this form. Perhaps the most difficult question in the methodology of science is: how does one move from observations to laws? How can one validly infer a universal statement from any number of existential statements?

Inductivist methodology supposed that one can somehow move from a series of singular existential statements to a universal statement. That is, that one can move from ‘this is a white swan', “that is a white swan”, and so on, to a universal statement such as 'all swans are white'. This method is clearly logically invalid, since it is always possible that there may be a non-white swan that has somehow avoided observation. Yet some philosophers of science claim that science is based on such an inductive method.

Popper held that science could not be grounded on such an invalid inference. He proposed falsification as a solution to the problem of induction. Popper noticed that although a singular existential statement such as 'there is a white swan' cannot be used to affirm a universal statement, it can be used to show that one is false: the singular existential statement 'there is a black swan' serves to show that the universal statement 'all swans are white' is false, by modus tollens. 'There is a black swan' implies 'there is a non-white swan' which in turn implies 'there is something which is a swan and which is not white'.

Although the logic of naïve falsification is valid, it is rather limited. Popper drew attention to these limitations in The Logic of Scientific Discovery, in response to anticipated criticism from Duhem and Carnap. W. V. Quine is also well-known for his observation in his influential essay, "Two Dogmas of Empiricism" (which is reprinted in From a Logical Point of View), that nearly any statement can be made to fit with the data, so long as one makes the requisite "compensatory adjustments." In order to falsify a universal, one must find a true falsifying singular statement. But Popper pointed out that it is always possible to change the universal statement or the existential statement so that falsification does not occur. On hearing that a black swan has been observed in Australia, one might introduce ad hoc hypothesis, 'all swans are white except those found in Australia'; or one might adopt a skeptical attitude towards the observer, 'Australian ornithologists are incompetent'. As Popper put it, a decision is required on the part of the scientist to accept or reject the statements that go to make up a theory or that might falsify it. At some point, the weight of the ad hoc hypotheses and disregarded falsifying observations will become so great that it becomes unreasonable to support the theory any longer, and a decision will be made to reject it.

In place of naïve falsification, Popper envisioned science as evolving by the successive rejection of falsified theories,rather than falsified statements. Falsified theories are replaced by theories of greater explanatory power. Aristotelian mechanics explained observations of objects in everyday situations, but was falsified by Galileo’s experiments, and replaced by Newtonian mechanics. Newtonian mechanics extended the reach of the theory to the movement of the planets and the mechanics of gasses, but in its turn was falsified by the Michelson-Morley experiment and replaced by special relativity. At each stage, a new theory was accepted that had greater explanatory power, and as a result provided greater opportunity for its own falsification.

Naïve falsificationism is an unsuccessful attempt to proscribe a rationally unavoidable method for science. Falsificationism proper on the other hand is a prescription of a way in which scientists ought to behave as a matter of choice. Both can be seen as attempts to show that science has a special status because of the method that it employs. — Banno

Summary: falsification applies to universal sentences, such as ∀(x)(fx⊃gx). For an open domain, no amount for evidence can show that everything that is f is also g. But a single example of an f that is not g can serve to falsify it. Hence, falsificaton serves to show which universals are false, but not which are true.

Universal sentences cannot be shown to be true in an open domain. If the universal sentence is also for some reason unfalsifiable then it cannot be shown to be either true or false.

Caveats:

• The claim only works if restricted to synthetic empirical universals in open domains.
• Shown to be true/false here means being empirically demonstrated.

This is basic, naive fallibilism at it's core. All sorts of complications and complexities follow. But understanding the logic of falsification is central to following argument concerning scientific method.