Dear Mr. Romero,
Thanks for the citation. I meant that Von Hildebrand does not define "value" by way of genus plus specific difference--the most precise way of defining a term.
First, he does not give the genus of "value." Is "value" a substance? Is it an accident? If an accident, is it a quality? If a quality, is it a habit? If a habit, is it an entitative habit?
Second, he does not give the differentia (specific difference) that sets apart the species "value" from other species within the same genus. In other words, if "value" is an x, i.e., a member of a broader group or genus called "x" (I call it "x" because Von Hildebrand does not tell us what it is), then what sets apart "value" from other x's (i.e., from other members of the genus x)?
Or, perhaps "value" is not something that can be defined. If that's the case, then it would be good if he told us so. But he doesn't. Thomists, for example, don't think it is definable. And they give good reasons why it is not definable.
(They don't call it "value," because that term connotes a certain subjectivity, as if the value of something depended on a person that "values" that something. And although Von Hildebrand would definitely deny that values are "subjective," nonetheless the term in itself does have that subjectivist connotation and if one adopts that terminology one constantly has to remind--or, rather, convince--oneself, and especially one's students, that there is no subjective subjectivist connotation. Thomists rather prefer the term "the good." Things are just "good"--regardless of a person who "values" those things.)
The "good" is not always an accident or a substance, but a transcendental--that is, a term that transcends all 10 categories (or genera), because it is found in all the categories. So, "good" is undefinable, because it is not bound by any genus (or category). In fact, as Aquinas likes to say, ens et bonum convertuntur: that is, good is coextensive, and therefore convertible, with being--which is also undefinable, for the same reason.