Rootlessness of Western Thought

Just one thread I attempted to follow in this post, before I decided to reign myself in and spread things out over multiple posts, has to do with Heidegger's ideas about the Greeks, at least as they appear in Poetry, Language, Thought. In the essay "The Origin of the Work of Art", he tries to get to "the thingness of the thing". In the course of doing so, he goes over the ways in which we normally think of a thing, for example its properties or physical characteristics (hard, soft, heavy, light, rough, smooth, etc). But:

What are we thinking of when we now have the thing in mind? Obviously a thing is not merely an aggregate of traits, nor an accumulation of properties by which that aggregate arises. A thing, as everyone thinks he knows, is that around which the properties have assembled. We speak in this connection of the core of things. The Greeks are supposed to have called it to hupokeimenon. For them, this core of the thing was something lying at the ground of the thing, something always already there. The characteristics, however, are called ta sumbebekota, that which has always turned up already along with the given core and occurs along with it.

These designations are no arbitrary names. Something that lies beyond the purview of this essay speaks in them, the basic Greek experience of the Being of beings in the sense of presence. It is by these determinations, however, that the interpretation of the thingness of the thing is established which henceforth becomes standard, and the Western interpretation of the Being of beings stabilized. The process begins with the appropriation of Greek words by Roman-Latin thought. Hupokeimenon becomes subiectum; hupostasis becomes substantia; sumbebekos becomes accidens. However, this translation of Greek names into Latin is in no way the innocent process it is considered to this day. Beneath the seemingly literal and thus faithful translation there is concealed, rather, a translation of Greek experience into a different way of thinking. Roman thought takes over the Greek words without a corresponding, equally authentic experience of what they say, without the Greek word. The rootlessness of Western thought begins with this translation. (All italics in the original; translation by Albert Hofstadter.)

This idea fascinates me, and I will be returning to it here. (As I will to the more difficult language--the thingness of the thing, the Being of beings, etc. But one thing at a time, please.)