Things are defined by their differentiation from other things, as you stated correctly. Objects and concepts only exist as separate from other objects and concepts to the degree our minds can differentiate the objects and concepts by those things which are NOT held in common between them.
Let me add some words in read to clarify what you are saying.
(Actually existing)Things are defined (electively by us) by their differentiation from other things, as you stated correctly. Objects and concepts only exist as separate from other objects and concepts(according to our ability to perceive the difference) to the degree our minds can differentiate the objects and concepts by those things which are NOT held in common between them.
Object Perception Our mind differentiates concept formed
"Things" exist everywhere at all times. All with which we can interact, including what appears to be empty space, is occupied by "things." Shared labels for these "things" require belief (in the separateness and distinctness of the thing labeled) and consensus (a predominance of population that agree to the separateness and distinctness of the thing labeled).
Sharing our labels is what language does. Whether or not our labels become the standard label for others is an arbitrary matter of convention.
Scientific labels are used in the scientific community. Informal groups use informal labels (A whore can be called a Ho, but, both labels refer to the same object.) Consensus is only necessary when we all wish to communicate clearly to each other by making our indicators as precise as possible (being defined for all to see.) Neither the label nor the consensus insures against delusion, misperception or hysteria. (UFO sightings, Bigfoot, Elvis sightings, Alien abductions, etc.)
Instead of childishly taunting and demeaning me, demonstrate an exception, please, if you can. Let us use your example of a forest fire: what is fire?
Wasn't aware I was taunting you. I actually thought we had a discussion going on!
Fire is a chemical reaction involving fuel and oxygen in which the intensity of the conflagration is proportionate to each. Does this really need defining? Fire is a common experience even among Geico cavemen!
Or for that matter, what is a forest, objectively speaking? How many trees make a forest? What size must they be. How much land area must be covered and to what density?
Hard for me to think you aren't aware of the proliferation of trees. Also hard for me to think the number of trees (which may or may not constitute a forest) is the conceptual common denominator to either the danger of fire or the point I was making.
In society we decide to agree on standards for our own common use and ease of communication. Some words are precisely defined when they involve money, medicine, technology and such. Other words are loosely defined because the actual numbers or descriptions are less vital to our useage. For example, the "inch" is shared by Great Britain and the U.S.A. which was based on, I believe, the distance across some king's thumb. A "foot" was the length of (I think Henry VIII) actual foot. A yard was the distance around his waist. Etc. Etc. It is an arbitrary unit which all agree upon and the STANDARD enables us to all be on the same page when discussing the particulars of measurement.
Other conventions are agreed upon such as the manipulations involving mathematics so that everybody does the operations the same way guaranteeing identical answers.
You are confusing the method with the object of the method. You are confusing the agreement with the reality of reference.
Non-contradictory measurement only needs an agreed upon standard and an agreed upon methodology to consistently produce the same results.
Incidentally, the usual method for destroying the clarity of a discussion is to pretend the elements of discussion are impossible to define or to focus on the non-essentials and make them a side issue.
I think you will find any "objective" reality you put before me can be similarly dismantled with ease, because labels are subjective.
Reality is always objective. It exists. Labels make communication between people easier since we are all speaking the same language. The fact you have chosen to speak English indicates how imporant this is. Your words (english language) are labels.
To the extent we use language (labels) according to agreed upon grammar (what we are taught to do in school for this reason) we understand and clarify our conversation.
To the extent we blur distinctions, pretend contexts aren't important or try to divert attention from the object of our discussion we obscure and muddy the subject.
Nobody is saying labels are not subjectively chosen. But, once the labels are agreed upon they become objective representations of the actual object they are referring to. The words German Shepherd are subjectively chosen letters and words and sounds, but, we all agree on what they objectively refer to when discussing breeds of dogs. Surely you can admit that!