This was one of the first subjects that came up during philosophy in the first year of high school. It is something that has occupied me on and off for years afterward.
The assignment was about writing if a robot could be a human. The debate at some point arrived at what ANYTHING was anyway. What is a human? What is a robot? What is a table? What is a chair?
Is saying something is a chair an opinion?
(Why do we always use "chair" as a concrete example instead of "foo" in philosophy?)
"This is a chair" is the statement that a particular object falls under a certain definition of "chair." The definition is an opinion, and the particular relevant qualities of the possibly-a-chair can also be disputed, but if both the definition and qualities are agreed upon, in the
ideal case the truth value of "this is a chair" should also be agreed upon. So I suppose that is-statements, under my view, can be reduced to a comparison between a definition and a set of qualities of an object.
Can be an opinion, based on your chosen axioms. Generally, if you're working off an agreed definition of chair, identifying something as belonging (if perhaps not exclusively) to that category can be considered a(n attempt at making, since you could just be kinda' wrong) statement of fact. Other stuff falls out along those lines.
Don't forget disagreements of qualities! Simple things like
color can have this problem, so with qualities like "is conscious", it's
bound to be tricky to pin down whether a given entity has that quality or not.
Now, if you ain't got that agreement you're having a roll in the hay with solipsism or something in its general direction and all bets are off, save that the proper response is probably going to be to ignore whoever's disagreeing's inanity and throw things at them until they go away.
There's always a practical limit to philosophy - I like to use the example of a philosophy that states the exact opposite of induction. That is, the more often something has happened, the less likely that it will occur in the future, according to "exduction". Suppose you try to prove to an "exductionist" that
eir philosophy is wrong - you could tell em that induction has always worked in the past. "Ah," ey say, "but according to exduction, that makes induction even
less likely to be correct!" Exduction is philosophically sound and utterly impregnable to any argument against it, but no sane person would adopt it. Sometimes you have to just throw things at people until they go away, as you say.
Context very important. Whether a sentence is an opinion or not isn't always inherent in the sentence. Could be an argument of chair vs throne with no clear distinction.
But are what we think of as factual statements about reality "opinions"? No, that's not the normal way to use the word "opinion". Doesn't matter if you might be wrong or disagreed with. Opinion isn't perfectly defined, but it definitely isn't that.
What is a fact, then? Everything is disputable - how do we tell between disputable facts and disputable opinions? Is "factness" a matter of utility rather than a fundamental metaphysical quality?
Context very important. Whether a sentence is an opinion or not isn't always inherent in the sentence. Could be an argument of chair vs throne with no clear distinction.
But are what we think of as factual statements about reality "opinions"? No, that's not the normal way to use the word "opinion". Doesn't matter if you might be wrong or disagreed with. Opinion isn't perfectly defined, but it definitely isn't that.
But can't something that is a chair to one person be not a chair to someone else?
Just as something that is beautiful to one person be not beautiful to someone else?
What is the difference between an evaluation of "chairness" and of "beauty" ?
I would argue - there is no
fundamental difference, but one of them relies more on agreed traits. Both beauty and chairness depend mostly on the form of an object, but beauty means "this is a pleasant form", while chairness means "this is a thing that is used to support a posterior." Even if these definitions are shared between two humans, judgment of pleasantness is more likely to vary than posterior form. If there were an intelligent species such that all members had the same sense of what pleased them, but rather different posterior forms, this conversation would be reversed - "beauty" would be truth and "chairness" opinion!
I guess I'll have to be the devil's advocate: if you consider Truth to be only truth if it's a statement that is always true, then saying it's a chair is only a correct opinion at best, not a fact.
Consider: There is no ultimate universal definition of what a chair is and what constitutes it (Tragically, Webster's is not the ultimate universal arbiter of what is), so by that definition what a chair is can only be opinion (i.e. an opinion as to what definition of chair is proper to use). In addition, definitions may change over time, making what was true false & vica versa. So correct opinions are all we have left.
It's correct because it most certainly is a chair by the definition you have chosen to use using, but it's an opinion because "chair" is just a name for something and not something intrinsic to the object itself. Another example is the concept of Day & Night: they're just a perspective on the motion of the earth, and what you see on the surface of the earth is not true for all observers (someone in space might see no such movement at all; to them, the concept is false). But if it's only true for certain observers following certain definitions, it is an opinion). Truth is something, ah, higher than that, like mathematical, scientific, and philosophical proofs. Sure the means by which you express these might be specific and limited, but the idea itself is something that is the same for everyone in the universe, everywhere, forever. Infinite applicability within its own defined rules, a statement about what is. That is truth.*
I'd argue a bit more subtlely than that, but our views on is-statements seem to be rather similar. (My concise description of is-statements is "the statement that a set of qualities of a particular object, and a definition [a mapping between a word and a concept, specifically a concept covering possible sets of qualities], match.") Furthermore, you seem to be saying that if something is necessarily common between all people, then it can considered to be true. That's basically my view too.
However, mathematics itself still has axioms! If those are not opinions, then what is?
(By the four hells, we are literally discussing what the meaning of "is" is. We are haunted by Bill Clinton!)
Both chairness and beauty are questions of aesthetics, so they can only be philosophical opinions. Imagine something most people would accept is a chair but is actually the vital component of a cow-butchering machine. Removed from its context it gets put in a different heuristic set by human minds, unless they have the detail of knowledge to always recognize it's built purpose.
Ah, but if somebody just
thinks it's a chair, does that make it
really a chair?
The real question is: Is philosophy a severe form of mental illness that happens to be ubiquitous in human minds, and will we be forever trapped in conflict with all alien races for being inherently and infectiously sick?
After looking at epiphenomenalism, I'd say "definitely and vigorously yes." In fact, I
will say that.
Well, the easiest answer would be to look back to Plato's Forms, though if you prefer something a bit more complicated you can always try Aristotle's.
Bah, Plato's just asserting that the real world is but shadows of an even realer world.
Why does ey think that? There can't be any physical evidence for this, can there? As I see it, it's useless to simply present a line of thought without backing it up by connecting it to an agreed-upon basis of commonality. And what fundamental commonality can there be, save physical experience and pure logic? And logic itself can only be used to
connect things - pure truth is useless on its own.
Is saying something is a chair an opinion?
Realistically, anything I place my ass on is a chair. Therefore, I am expressing my opinion that something is a chair by sitting on it. My opinion could be incorrect if the thing I sit on breaks or something. Or it could be a very poorly made chair, who knows.
It could be even more of a chair if all I ever do with it is place my ass on it.
If you rest your ass on it for even a moment, you have made the object factually a chair. Wither or not it was a good idea to create that particular fact is irrelevant, because a chair is a thing you put your ass on and you put your ass on that thing.
But how do you know that "chair = thing that has had a posterior on it" is true?
Is mayonnaise an instrument?
That depends on the definition of "instrument"! As well as the definition of "mayonnaise," but that involves less ambiguity than "instrument."