It is the difference between subjective reality and objective reality. Subjective, by definition, means it depends on perspective (a subject). Objective is the opposite, it does not depend on perspective, it is true for all perspectives.
In a certain capacity it is possible to know something subjective. If you are looking at something — say, a bird — that I can't see from where I'm standing, I can move to where you are standing, and be able to see the bird myself from where you were standing.
But location is only one level of abstraction from which we understand perspective. Time is also a factor. What if, in the time it took for me to move to your spot, the bird flies away, and I miss it? Then it becomes clear, I didn't have the same perspective that allowed me to spot the bird.
This path of further specifying the extreme detail which makes up a subjective experience ultimately leads to impossible requirements like being in the same mental state, having had enough sleep the night before — in the last resort, having lived all the same experiences until that present moment, and having an identical physical body throughout the whole process. There can be no true knowledge of a subjective experience without experiencing the exact same thing, in all of the specificity that entails. In a word, without being the same subject.
We can know objective facts which are independent of perspective, such as empirical measurements like temperature and pressure, all the way up to more complex facts like "we live in a society of commodity production and exchange." But those are objective because different observers can verify them empirically, like the color blue in the OP's post.
An additional thought... the history of science is essentially the history of finding objective facts, facts which are true regardless of perspective. Even physics, being perhaps the most basic and immediate field of research, has struggled to find an end to the manifold perspectives which can overthrow what we had thought were objective facts.
One can of course point to the discovery of the round earth, or of heliocentrism. But it goes further.
We thought we were pretty smart when we figured out classical mechanics and thermodynamics. Lord Kelvin famously said,
"There is nothing new to be discovered in physics now. All that remains is more and more precise measurement."
This obviously turned out to be false because, when you look really closely at stuff, quantum mechanics starts to change everything. What we thought were particles with definite positions and moments, at last revealed themselves to be indeterminate wave-ish things.
For that matter, general relativity a few decades prior had upended our most basic notions of time and space. We thought we were safe saying the Sun is at such-and-such position 150 million kilometers in blah direction, and it is 5 billion years old, etc etc. But because the speed of light is constant regardless of your motion, this forces us to accept that other observers might observe the Sun somewhere else and perhaps a different age than what we perceive. Thus the name relativity; there is in fact no objective frame of reference. In science we use the inertial frame as the default, but it is arbitrary and not intrinsically more correct than the frame on the event horizon of a black hole.
Even in my previous comment, where I listed temperature and pressure as objective, to claim those as objective it is necessary to specify (implicitly in my case) some location and time which give validity to calling them objective.
So it is always the case, for any objective fact, that it depends on a set of assumptions about what is sufficient to call a perspective "the same" enough that it can be said that two subjects share a perspective. This abstract sense of shared perspective is what gives rise to "objective" facts, which may in fact not be objective for the whole universe. But as a practical matter it is usually only necessary to assume things which are common to all, such as being on Earth, living in 2023, being a human, etc.
An additional thought... the history of science is essentially the history of finding objective facts, facts which are true regardless of perspective.
I agree with basically everything you've said throughout your post, but I do want to emphasize that even this got thrown out the window in the mid-20th century with the work of Kuhn and Quine. Scientific realism is currently trying to mount something of a comeback, but some rather compelling work in history and philosophy of science says that the notion of objective facts needs to go out the window.
Interesting, I'll have to look into those authors you mentioned. I agree, there does seem to be a shift away from a clean separation of objective and subjective, toward a more refined attitude of true given these assumptions, i.e. an emphasis on the scope of validity for a given fact, and never believing for a second that we've found the absolute end of science, scoped out all of the hidden assumptions or miscategorizations we didn't realize we held.
It is the difference between subjective reality and objective reality. Subjective, by definition, means it depends on perspective (a subject). Objective is the opposite, it does not depend on perspective, it is true for all perspectives.
In a certain capacity it is possible to know something subjective. If you are looking at something — say, a bird — that I can't see from where I'm standing, I can move to where you are standing, and be able to see the bird myself from where you were standing.
But location is only one level of abstraction from which we understand perspective. Time is also a factor. What if, in the time it took for me to move to your spot, the bird flies away, and I miss it? Then it becomes clear, I didn't have the same perspective that allowed me to spot the bird.
This path of further specifying the extreme detail which makes up a subjective experience ultimately leads to impossible requirements like being in the same mental state, having had enough sleep the night before — in the last resort, having lived all the same experiences until that present moment, and having an identical physical body throughout the whole process. There can be no true knowledge of a subjective experience without experiencing the exact same thing, in all of the specificity that entails. In a word, without being the same subject.
We can know objective facts which are independent of perspective, such as empirical measurements like temperature and pressure, all the way up to more complex facts like "we live in a society of commodity production and exchange." But those are objective because different observers can verify them empirically, like the color blue in the OP's post.
An additional thought... the history of science is essentially the history of finding objective facts, facts which are true regardless of perspective. Even physics, being perhaps the most basic and immediate field of research, has struggled to find an end to the manifold perspectives which can overthrow what we had thought were objective facts.
One can of course point to the discovery of the round earth, or of heliocentrism. But it goes further.
We thought we were pretty smart when we figured out classical mechanics and thermodynamics. Lord Kelvin famously said,
This obviously turned out to be false because, when you look really closely at stuff, quantum mechanics starts to change everything. What we thought were particles with definite positions and moments, at last revealed themselves to be indeterminate wave-ish things.
For that matter, general relativity a few decades prior had upended our most basic notions of time and space. We thought we were safe saying the Sun is at such-and-such position 150 million kilometers in blah direction, and it is 5 billion years old, etc etc. But because the speed of light is constant regardless of your motion, this forces us to accept that other observers might observe the Sun somewhere else and perhaps a different age than what we perceive. Thus the name relativity; there is in fact no objective frame of reference. In science we use the inertial frame as the default, but it is arbitrary and not intrinsically more correct than the frame on the event horizon of a black hole.
Even in my previous comment, where I listed temperature and pressure as objective, to claim those as objective it is necessary to specify (implicitly in my case) some location and time which give validity to calling them objective.
So it is always the case, for any objective fact, that it depends on a set of assumptions about what is sufficient to call a perspective "the same" enough that it can be said that two subjects share a perspective. This abstract sense of shared perspective is what gives rise to "objective" facts, which may in fact not be objective for the whole universe. But as a practical matter it is usually only necessary to assume things which are common to all, such as being on Earth, living in 2023, being a human, etc.
I agree with basically everything you've said throughout your post, but I do want to emphasize that even this got thrown out the window in the mid-20th century with the work of Kuhn and Quine. Scientific realism is currently trying to mount something of a comeback, but some rather compelling work in history and philosophy of science says that the notion of objective facts needs to go out the window.
Interesting, I'll have to look into those authors you mentioned. I agree, there does seem to be a shift away from a clean separation of objective and subjective, toward a more refined attitude of true given these assumptions, i.e. an emphasis on the scope of validity for a given fact, and never believing for a second that we've found the absolute end of science, scoped out all of the hidden assumptions or miscategorizations we didn't realize we held.
You're getting very close to Quine's confirmational holism there. Cool stuff all around.