The man is pleased with your request; he immediately returns to the discussion of horses. As he does so, he walks you over to one of the display cases. Inside is a diagramme of the metaphysical kingdom of horses. It is a colourful array that highlights and distinguishes all the particular details contained within. Everything is clearly related to everything else, and together they form a coherent Whole.
Wonderful, let's discuss the topic of "horse" in its most general sense. Does "horse" refer to all of the horses? Yes, but it's also broader and more complex than one might expect. If you round up horses you will have a herd, but even that is more limited than the meaning I wish to express.
The term "horse" can also reference the horses in your mind's eye. It can go beyond that and capture the relationships between all of these. It can even be used to capture their external relationships with the rest of reality. The metaphysical kingdom of horses may constitute a unity of impressive scale and complexity. If we plot it out, we will see their complete domain and existential network.
But given that we might use different definitions or scales for "horse", what is the objective meaning of the word? I fear that question may result in a semantic game; we are using the term in the context of this conversation, so we need only consider whether I am using it in a way that coheres or otherwise picks out meaning. For today, let the speaker be the measure of what is said, avoiding the discussion of whether a string of letters has a definition superior to the immediate, intended meaning.
Anyway, put aside that distraction. Think back to what we said about broadening and narrowing our scope. There was a reason we distinguished between the scope that covers a whole horse, and the scope that only considers the leg. We can say that a particular horse is real because it possesses something beyond each individual detail or constituent. There is meaning in its very arrangement. Because we perceive this meaning, we must acknowledge that it "is", and absent some alternative it "is" in an absolute and inviolate sense. The unity is no more or less real than the constituents.
Some might ask whether the fact of unity itself, described as an arrangement or set of relationships, is not a constituent part of the horse. If that is the case, a horse really might boil down to a collection of parts with no loss of meaning; you could separate each leg and each relationship and consider all these things independently. Problems immediately arise. For example: even if we wanted to adopt this model of parts, consisting of limbs and "relationships", we cannot handle all the parts the same way. I mean, the "relationships" inherently involve the existence of the things being related. By handling the "relationship" part, we would necessarily admit the whole. In terms of the leg, people might at least argue that it is a unit that could stand alone, although that too is false for a number of reasons.
I have to say, in such a model there would be no end to the division. We might subject the leg to the same treatment as the horse, leaving us with the flesh and bone. We may then subject the flesh and the bone to the same treatment, and so on. By failing to be steadfast in our conviction that meaning is omnipresent, we will be unable to find any secure foothold for meaning. Now imagine if we play a game and ask if the parts have magnitude; if there is no limit to division, and each division has magnitude, then maybe we will all be crushed under the weight of an infinitely massive horse.
Obviously I am joking, sorry. I will spare you the talk of famous paradoxes and other fun puzzles. There are people here who are fond of them, perhaps you will visit them later; they also take a special interest in questions of change and motion. I sympathise with them, to some degree; they highlight the absurdities involved in the common accounts of such things, inspiring outsiders to adjust or otherwise clarify their position. Those outsiders usually wind up shifting closer to our own views, for Eleatic philosophy is not prey to such absurdities.
Yet, I want us to speak in our own right; we must put forward an affirmative case. To be blunt, this talk of parts is rife with errors. "Things" and "relationships", "matter" and "form", whatever other system people may come up with, it's all very troublesome. There is Being, which in its perfection subsumes all coherence. The horse is a detail. The leg is a detail. The flesh and bone are details. Don't treat parts as ontologically independent entities, don't divvy them up and lose focus of the whole continuum, and don't dilute existence and posit ephemeral layers of being. I could go on, but you'll do well so long as you remember that reality is omnipresent and uncompromising. We're describing its details. We are its details.
The man nods, satisfied with his speech. He appears to have worked himself up a bit at the end there.