Does a "fact" have to be true?

I think that you are reading too much into the last two definitions listed. The fifth one is apparently a legal term of art and as we all know lawyers have little use for the actual truth. The fourth covers instances where facts are asserted without being verified. If I asked a group of toddlers for a list of facts about where babies come from, that's still a list of facts.

Finally, the same argument can be made for truth, "a fact or belief that is accepted as true" being one of its meanings. So now we're trespassing into the realm of epistemology.stackexchange.com.

From Hard Facts: nuances in meaning and usage exist, but there are good reasons to use both terms:

• What is the clear difference between a fact and a truth? Well, if you look into most dictionaries, you will be amazed to find that the two words are actually very close in terms of their definitions. This is because the two terms are very much related. That’s why you really can’t blame people for recognizing both as similar terms.

• Fact is basically something that exists, or is present in reality. Hence, these are things that can be seen visually, and these are the things that can actually be verified. Facts are objective matters rather than subjective ones. It is not just something that you believe, but rather these are more or less the things that can be observed empirically, or by the senses. So, facts can be seen and heard, as well as proven by the other senses.

• Truth can be described as the true state of a certain matter, may it be a person, a place, a thing or an event. It is what a person has come to believe. If he believes that something is true, then it is true. It also answers the questions of what’s really happening. In the technical sense, facts can answer certain ‘why’ questions, like ‘where’ or ‘when’, and even ‘how’, while truth answers the question ‘why’. The question of ‘how’, and even ‘what’, are said to be answerable by either of the two.

• In terms of permanence, a fact happens to be more permanent, and almost always seems to have no changes. It is more constant than truths. For example, when you say that the sun will always rise from the east and set in the west, you are telling a fact, but when you say that you are in Los Angeles, then that is a truth, at least for that exact moment. Several hours from that time you may have gone somewhere else, making your previous statement a fallacy. Thus, a truth is something that is not universal, it is more subjective, and depends on the current situation. That’s why the truth’s existence is said to be more temporary than that of facts.

  1. Facts are more objective when compared to the more subjective truths.
  2. Facts are more permanent when compared to the more temporary truths.
  3. Facts exist in reality, whereas truths are usually the things that one believes to be true, or the things that are true in the current situation.
  4. Facts can also answer the ‘where,’ ‘when’ and ‘how’ questions, whereas truths answer the ‘why’ question.

"What I'm really after... is whether the adulteration of this particular word renders it...meaningless, and therefore something to be avoided."

The word is not being "adulterated"; it is being used in different ways in different speech contexts.

A fact is that which exists or existed, happens or happened, and which can, as a result, be *known, thought, supposed, believed, stated, averred, alleged, etc".

These ancillary definitions involving speech contexts are not really definitions of "fact" per se but of the kinds of mental attitudes we can express, or the kinds of predications we can make, in respect to ontological fact. The lexicographers have made a leap from ontology to (everyday) epistemology.

There are some good answers here. I thought it would be useful to expand on meaning (5) in your list, in case you ever have to deal with it.

In English common law, most matters (criminal or civil) came to be tried by a jury. Over time a rule developed that some questions would be decided by the jury and others by the judge. The jury decided questions of fact whereas the judge decided questions of law.

For example, in the English law of theft, one element of the crime that must be established by the prosecution is that the defendant acted "dishonestly". The meaning of "dishonest" is a question of law, but whether the defendant was dishonest according to that definition is a question of fact.

There are practical consequences of this distinction. In English criminal procedure, you may appeal the judge's decision on questions of law, but not the jury's decision on questions of fact.

In this usage "fact" is used in a slightly technical sense in opposition to the word "law" but it is essentially intended to be restricted to statements that are true, at least that is the hope.

There are basically two types of facts: Universals, which are universally true and is usually part of common sense about how the physical world works, and Facts that are statements you believe are true, but not necessarily.

In your precise case, about the usage of the word "fact" for communication purpose, we must also account for the incompleteness and incertainty of the interlocuter: he/she may be using a prejudice that is just false, or be lying, or just misestimating his/her level of confidence in the statement he/she made.

So, in the end, a fact can only be what one believe is true, as opposed to what is true universally.

BTW, this is a very important topic of research in knowledge representation, logics, artificial intelligence and in any epistemological system (ie, systems that represent knowledge) in general.

Your question sounds as if you are in a Quixotic fight against a particular false Scotsman, not realising that there is no such thing as a true Scotsman, or for that matter, a true X for any word X whatsoever.

You could just as well be "struggling to decide whether to jettison use of the word word, because the definition appears to be not solid enough to support continued usage". There is no clear boundary between what is a word and what isn't. Is "ouch" a word? Or "hmmm"? How about "Aargh"? "Aaaaaaaaaaaaaaaaargh"? Is "blasé" an English word? What about "révisioniste"? Is "Agatha"? And "Christie"? Is the symbol used by 'the artist formerly known as Prince' a word? Is "a priori" an English word? Or is it two? How about the two constituents? Note also that in languages which do not separate words by spaces, it can be practically impossible to distinguish separate little function words from suffixes or prefixes.

Who is this I who is struggling anyway? Do you mean your body, your mind (whatever that is) or your soul (whatever that is)? Did this I already exist when 'you' were born and possessed only a tiny percentage of the atoms that you would now consider your own, whereas many of the atoms 'you' possessed then have found something else to do in the meantime? Did it already exist before you could think clearly and create memories that you can still draw on?

What do you mean by struggle to decide? Who is this ominous person trying to prevent you from deciding, the one you apparently have to struggle against?

What do you mean by the definition? Since when do words have unique, well defined definitions? Where would you be able to find the one true definition of a word? How would you be able to understand it without using similar definitions for all the words used in it, leading to loops and an infinite regress?

Facts are true because (in some sense that I don't wish to make precise) the meaning cloud for the word fact is mostly a subset of the meaning cloud for the word true. Although false facts are mostly outside the one for true, while still in the periphery of the one for fact.

For similar reasons, birds can fly even though some birds have broken wings or happen to be penguins. And facts are true even though some are not.

When I refer to something as a fact, without qualifications, I am implying that it is true. This situation is not much different than when I say something like "I ate a grapefruit for breakfast." I am implying that I actually did. I might be lying, but the meaning of my sentence is that my eating of a grapefruit is the truth. I can refer to an event as alleged, no longer implying it is necessarily true: "Allegedly, he ate a grapefruit for breakfast." Similarly, I can use the word fact to refer to that event, whether true or not: "The alleged fact of your eating a grapefruit is immaterial to the question at hand." It is possible to drop the word alleged in this last sentence, and without it, the sentence will be ambiguous about whether I am implying that you did eat a grapefruit. Some people will interpret it to mean I implied you did, others will interpret it to mean I am agnostic.

Does a “fact” have to be true?

No.

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Here is a detailed definition of fact from OED for the sense that we are dealing with:

A thing that has really occurred or is actually the case; a thing certainly known to be a real occurrence or to represent the truth. Hence: a particular truth known by actual observation or authentic testimony, as opposed to an inference, a conjecture, or a fiction; a datum of experience, as distinguished from the conclusions that may be based on it.

But it is also mentioned that:

Where the truth of a matter is disputed or in doubt, this sense overlaps with sense "A piece of information allegedly or conceivably true; something presented as a fact but which is disputed or unproven; (more strongly) an unproved assertion, an allegation."

In fact, the truth is, it depends.

You understand that the fact is not a truth from the context. Usually, the negative words like false, unproven, disputed etc. reveal that. (They might modify fact also.)

Some examples from OED:

• This is..a false fact, supported by a supposed motive - 1824, Westm. Rev.

• It bases its accusations on false statements and inaccurate facts. - 1941, A. M. Lindbergh Diary

• Waksal hotly disputed some of the facts in that story. - 2002, Vanity Fair

_{Note: Of course it can be discussed or interpreted further but I focused on the usage of the word.}

As the definitions you quote indicate, the word "fact" is used in two different senses. It can mean something that is true, or it can mean something that is claimed to be true, but which may or may not actually be true.

On the one hand, people will say things like, "It is a fact that Senator Jones accepted a bribe." Meaning, this statement is true. Or conversely, "No, that's not a fact at all." Meaning, that statement is false.

On the other hand, people also commonly say things like, "The facts are in dispute", meaning, we are arguing about what is true and what is not. Editors talk about "fact-checking" a document to determine whether the facts it states are true or not. We talk about "unproven facts" or "questionable facts". We say, "You have your facts wrong." Etc. If the word "fact" was understood to mean "statements that are true", then it would be a paradox to say "unproven facts" or "disputed facts" or "the facts are wrong". How can something that we all know is true be in dispute, etc?

Yes, a fact is a statement that has to be indisputably true.

The ever reliable NOAD confirms this:

fact |fakt| noun a thing that is indisputably the case

As does the even more reliable OED:

fact n. a thing that is known to be true

The Collins COBUILD dictionary supports:

fact - A fact is an item of knowledge or information that is true.

Some people use the word "fact" to stress a belief, but they can be corrected if what they believe isn't a fact.

Consider Donald Trump's statement that more people attended his inauguration that any other President's in history. He may believe it with every fibre of his being, but despite his belief, the statement is disputed by photographic evidence:

Other times people may misuse the word "fact". For example, someone might say:

Before 1917, people thought it to be a fact that the atom was the smallest particle of matter. Today, it is a fact that it isn't, and we were wrong in thinking it was...

This is false in both counts. No scientist would say, "it's a fact that the quark is the smallest particle of matter". Instead they would say, "it's a fact that the quark is the smallest known particle of matter". The first statement is a belief, the second is an indisputable statement of truth.

Here are some real examples to demonstrate this is how such statements are phrased in the real world:

• JLab Science - What is the smallest particle of matter known?
• What Is The Smallest Particle We Know? - Science ABC
• CERN: The building blocks of matter ("Today, physicists don't know of anything smaller than quarks and electrons, but they don't know for sure whether these are the simplest building blocks of matter.")

Anyone saying, "it's a fact that X is the smallest particle of matter", at any point in history (including the future) would not be stating a fact because we can never be completely sure we know the smallest particle of matter.

Another example of the misuse of the word "fact":

When a jury convicts a man, it's a fact that he's guilty. If he's later acquitted, it's a fact that he is 'not guilty'.

Again, both statements are false. All anyone can say after a court declares a guilty verdict is, "it's a fact that this person was found guilty in a court of law".

Even a court of law acknowledges its fallibility, which is why mistrials are declared.

Again, here's some real-life examples:

• Harvey Weinstein found guilty of rape - BBC News
• Fake Heiress Who Swindled N.Y.’s Elite Is Found Guilty - The New York Times
• District man found not guilty of fatal stabbing - Washington Post

Whether the person is actually "guilty" or "not guilty" remains disputable, and so is not stated.

Another example is how understanding can change over time. Prior to August 2006 it would have been factual to say, "there are nine known planets in the solar system". After Pluto was reclassified as a "dwarf planet", it has since been factually correct to say, "there are eight known planets in the solar system".

Both statements were facts at the time they were made, according to how humans classified planetary bodies when the statements were made. It's when the statements were made that defines if they were facts or not.

To repeat: A fact is always an indisputably true statement. If the statement can be disputed it is, by definition, not a fact.

This is why Collins adds the following caution to their definition:

Be Careful!
Don't talk about 'true facts' or say, for example, 'These facts are true'.

If a statement has the potential of being false, it is not a fact.

I'm not really looking for a discussion of truth in the philosophical sense. The scope of this question is limited to the meaning of a word in English, not the meaning of an absolute concept as rational beings can or should understand it.

I'm afraid you are looking for a discussion of truth in the philosophical sense, because you can't isolate the meaning of a single word that way. Nearly everyone agrees that facts are necessarily true; they disagree on what "truth" means. The de re definition of "fact" for any one person is "a true statement about the phenomenal world", but when one person writes out definitions for all the different usages of "fact", that person writes each definition de re with respect to his or her own definition of truth, so they all come out different. That's what accounts for all the different definitions of fact.

If you want to know how the word "fact" is used in English, that is quite different from what philosophers or mathematicians consider "fact". Here are some more definitions like the one you provided which seemed to prompt you to ask this question:

c. Something believed to be true or real:
American Heritage Dictionary

2:a piece of information presented as having objective reality
("presented as having" does not refer to "real" fact - whatever that means)
Merriam-Webster Dictionary

Other definitions are along the lines of:

"information known to be true".

Would you admit that I can "know" something and be wrong? If that's true, then all other dictionaries allow for "fact" to mean something which is NOT true scientifically/objectively/verifiably.

So if you are interested in how the word "fact" is used in the language itself, forgetting the rigorous definitions of truth and fact that have to do with verification, and leaving apart the special study of epistemology and all the philosophical stuff, it's clear to me that when used in our language "fact" does not always mean something that is true.

Let's say the basis of whether something is fact is a definition, like the IAU's definition of a planet. Pluto is no longer a planet, but a dwarf planet, making the statement "Pluto is not a planet" a fact. Suppose the IAU change the definition tomorrow. Has the fact changed?

An etymological note: fact comes from a term meaning simply "something done", as etymonline says.

fact (n.)

1530s, "action, anything done," especially "evil deed," from Latin factum "an event, occurrence, deed, achievement," in Medieval Latin also "state, condition, circumstance," literally "thing done" (source also of Old French fait, Spanish hecho, Italian fatto), noun use of neuter of factus, past participle of facere "to do" (from PIE root *dhe- "to set, put"). Main modern sense of "thing known to be true" is from 1630s, from notion of "something that has actually occurred."

A similar phenomenon has occured in Spanish, where two important synonyms for the English "fact" are hecho and dato, the latter which is immediately related to "datum" in English (see etymologias.dechile.net). This, because Latin facta is related to when [a letter] was made, and datum is related to when it was given, which, by the way, is another synonym for "fact" in English...

So the sense of a "changeable datum" has departed significantly from it's etymological origin, as indeed many words have. When once you have given something to someone, you cannot change the fact that it is given, even if you take it back; but a piece of information, once separated from its source, can be changed.

Don't jettison the word, but use it with care.

Etymology aside, here's the word, in the wild:

And as Felsenthal noted, it is one that will be put to the test. “I don’t think there’s ever been a president and vice president to take office in a moment like this, where we don’t just disagree on issues,” he said. “We disagree on basic facts.” (Washington Post, 10-12-2020)