If the nominalist intends to explain his theory to another, he might point to a rose, and say that what really exists is "that thing" which we "call" a rose. We call other things roses as well. But the universal, the "roseness" by virtue of which we call a rose a rose, does not belong to that object (indicating the rose before him). There is no such thing as "rose" or "the red," there are only things in the world to which we apply these names. Put another way, universals are not real, only discrete things are real (e.g., things we call roses, rocks, atoms, etc., but which are actually pure singulars). When Aristotle talks about a human nature shared between individual human beings, the nominalist will say, he is wrongly imposing a mental idea he has upon individual things. The common nature of roses really exists only in the mind, in reality we have only singular objects.
But Hegel notices something strange about such a proof. If we deny the rose has a shared nature, we cannot say that it is really either red or green (only that we call it that) that it is of a certain length (for length too is a universal), and so on. All characteristics (green, long, etc.) are universals, for these can be predicated just as well of other things. If the universals (red, green, long, prickly) do not really exist but are only imposed by the mind upon the thing, what is indicated as really existing is an object that is "pure being." The nominalist cannot say "that rose is what really is", for in such a case he would be saying that an instantiation of a universal is what really exists. Nor can he say "that green thing is what really is, we just call it a rose." He can only say "that thing is what really is."
But in asserting that the thing is what really exists in itself, the nominalist asserts the most abstract universal of all: the Thing or the object. For all that is, is a thing or an object; thing or object is the broadest class of universal.
What we say is: 'This', i.e., the universal This; or, 'it is', i.e., Being in general. Of course, we do not envisage the universal This or Being in general, but we utter the universal; in other words, we do not strictly say what ... we mean to say. But language, as we see, is the more truthful; in it, we directly refute what we mean to say, and since the universal is the true [content] of sense-certainty and language expresses this true [content] alone, it is just not possible for us ever to say, or express in words, a [particular thing] that we mean.The more strenuously the nominalist tries to assert that what really exists are singular beings, the more strenuously the nominalist actually asserts that what really exists is the abstract universal Thing or pure being. Even when the nominalist says "this is", the nominalist asserts the existence of a universal, for this can be predicated of a rose, a rock, or a house. Language undermines the nominalist's claim; the nominalist asserts the opposite of what he means.
One might suppose this is no problem for the nominalist, for of course language deals in universals, and so of course language imposes these universals on what really is. But in this case, the nominalist cannot provide an argument, for whatever he intends to say, he in fact expresses the opposite.