chewybrian wrote:Actually, it seems fair to go the other way, granting objective existence to matter and energy and questioning the objective existence of the object (even if you can't spell objective without "object"). The matter and energy existed before the object came into being, and will exist after it is gone. Presumably, they would exist without anyone to notice them for what they were. One could argue all objects are subjective, and they only become objects when a subject can recognize them for what they are.
My position is that the question of what we decide exists is all a matter of what is most useful for describing and predicting observations.
Matter and energy are essentially useful labels to indicate that the results of various mathematical equations will be the same. If we take, for example, the gravitational potential energy of a mass in a uniform gravitational field (mgh) and the kinetic energy of that mass when it is moving (1
) we find that as the mass moves around in that gravitational field the sum of those two equations stays the same. That allows us to make predictions as to how that mass might move in the future, with the result that we can design roller-coaster rides. So we decide that that sum corresponds to a physical quantity of something, and we call that something energy. And we invent laws like "energy is conserved" to embody that equality of those sums. We do the same for mass. And then we go on to say that "mass-energy" is conserved and we relate the units of one to the units of the other (E=mc2
). And so on.
So, this sense we have that those equations are measuring a "thing" which we might give a name, like "energy", might make us think of that thing as existing. If that works for us, fair enough. It doesn't really matter. Whether we think of it as a "thing" that "exists" or as a number in an equation, we still get to design that roller-coaster.
If there is no human available to recognize it, can a motorcycle still be a motorcycle? The motorcycle becomes an object because we can recognize it. The concept "motorcycle" also exists, in my view, because it can be passed on. The particular motorcycle would exist as long as it was possible for someone to recognize it for what it was. The concept "motorcycle" exists as long as there is a record of it, or someone who remembers what a motorcycle is. If all records and memories were gone, it would only have the potential to exist. Arguably, though, the existence of the real motorcycle or the concept could be said to be subjective.
A motorcycle is a composite object that is made by humans and labelled by us as "motorcycle" so, yes, we could say that there is a sense in which it only exists as a motorcycle if there are people to recognize it as such. I think this relates to the point about the Empire State Building made by Pantagruel in a later post.
I am presuming my own understanding of "objective", meaning that the truth of the matter is not dependent on any subject's understanding of it. For example, 2+2 is 4, despite my impression that it might be 9 or 3. Objective existence, in that sense, must mean existence that goes above and beyond my understanding or recognition.
I would say that an objective proposition is one that proposes something to be true for all possible suitably situated observers. i.e. it proposes that the tests of its truth or falsehood are publicly accessible. So the truth of the matter is not specific to any one observer. So, to use an example from Buddy Holly that I cited in another topic, this proposition is objective:
"it is raining."
while this one is subjective:
"It is raining in my heart."
I think it's tied to the concept of "object" not just because of the spelling but because "object" is a concept that we propose to be the reason why such propositions are true. We say: "the reason why I confidently make a prediction about an indefinitely large set of future sensations is that I believe in a concept called objective existence and I believe that the objects which exist are the cause of those sensations."
Whereas the example you cited from mathematics is true (or false) regardless
of any possible observations because it's true by the definition of the symbols used (2, +, 4 and =). That seems to me to be something a bit different from an objective proposition.