Crystals appear (on the scene of Reality) -- just like organisms -- always as individuals. Such an individual has a definite Identity that remains constant during its existence. It is, say, A, it is not B, not C, etc. A developing crystal of Salt (growing in a solution) can change its shape while its Identity remains the same. For organisms this applies even stronger. We ourselves (being an organism) seem to have direct experience of our Identity staying the same during all of our life in spite of the fact of the many changes we constantly undergo. Some insects undergo a strong metamorphosis (for example from caterpillar to butterfly) but nevertheless their Identity stays the same. So it seems for every entity, which is an intrinsic whole, that there is something that remains the same, and something else not remaining the same, but always changing. In Philosophy such changes are called "accidental" or "per accidens" in relation to the persistent Identity. This Identity is called the "intrinsic Essence" of the thing, so every real uniform being has such an Essence.
IDENTITY AS A PRINCIPLE
But what then is this Essence?
Where does it abide?
Does it abide outside the thing (as Plato assumed), or inside the thing (as his famous pupil Aristotle assumed)?
And if the Essence is located inside the thing (meaning that the Essence of every being abides in "our world", and not in some external immaterial world transcending the material world), which I consider the most probable position, where in the thing is it located and in what way? Could this Essence be a concrete part of the thing, the "heart" or "soul" of the thing, which implies that the Essence itself would also be a thing (and this thing should of course also have an Essence of its own........Oh my god, where are we going???), or is it in the thing in an abstract way (whatever that means), like a principle?
A background sketch: together with Joshua Levy, I am building a subject mapped social bookmarking application. We call it Tagomizer (tm). It's being fun. But, it's also causing (moi) brain pain. What is a subject? Let me translate. Someone bookmarks a webpage. This means that the URL of that page, and the page title, are sent to Tagomizer, which then paints a form in which the user can add tags (words or phrases for now, images and other objects later), and a body of text taken as a comment. A user can come in later and add more comments or more tags, or remove tags. Tags are a large part of Web 2.0, where folksonomies are breaking out everywhere.
What is a subject? When Tagomizer creates a bookmark, it creates several subject proxies in the subject map where those objects don't already exist. Tagomizer is a kind of TMA (topic maps application -- or SMA in the newspeak of the TMRM), so it is responsible for identification of its subjects, some of which might already have subject identity granted by other TMAs. What, then, is a subject? Consider the webpage itself. Tagomizer asks the core TMA to create a subject proxy for a webpage with a given URL. If that subject proxy already exists, it is returned. Otherwise, a new one is created and granted subject identity by way of a PSI associated with the core TMA. Tagomizer, as a different TMA then grants that subject proxy subject identity with a different PSI, one that says "this is a subject identified by Tagomizer." Other TMAs might grant an SIP (psi) of their own. This is necessary because each individual TMA will be adding other properties to the proxy, mostly assertions.
So, a webpage has granted to it subject identity. What is the subject? In this case, subject identity has been granted to a particular resource, a webpage. Nothing more than that. The resource exists, it is located on the web at a particular URL, and it has been granted subject identity based on that URL by one or more TMAs. Each TMA is going to confer other properties on that subject. We know from nothing about the subject itself other than those properties of location and object type. What is contained/presented at that webpage will be the subject(s) of other subject proxies, for which that resource becomes an instance of an occurrence.
Brain pain, for me (warning: admission of ignorance forthcoming), stems from notions of essence. Essence is mentioned in the quote above as an intrinsic issue. Now, we're deep into the same issues that come up from time to time in the OODB community, intrinsic vs. extrinsic properties. There's an interesting thread on web resource identity, not dissimilar to Bernard's previous post on URI ambiguity. That xml-dev thread starts here.
Intrinsice-extrinsic properties are discussed here.
Closure? Is closure possible? I post this because I am interested in looking for concensus reality related to interoperable ways in which subject identity can/should be conferred on the subjects of future topic/subject maps. My sense is that the inquiry I reveal in this post represents the, um, essense of this entire blog and of Bernard's inquiry. I'll take my answers anywhere I can find them.