Thanks to all who participated in the blogpoll "what comes first white or whiteness?" I trust those who said white didn't say so because it appeared before whiteness in the poll ;D Actually, both answers are correct depending on the order under consideration (existence or intelligibility). In the last analysis though, the question to be answered is what comes first, existence or signification? No prizes, but a good brushing for the neuron. Please read on... :-)
The dictionary states that whiteness is the quality of being white, and sees in it a principle (what comes first) of sorts. Yet it is when we see a white wall, snow, milk, a white cat, that intelligence abstracts the noun whiteness. Yet once you abstract the "universal" whiteness it seems that you see the singular whites differently, under the light of whiteness. If you had never seen white you wouldn't ask yourself what whiteness is, and if you did not understand what whiteness is you wouldn`t recognize white so easily. But you have never seen whiteness on your daily walk. White is what you experience in the first instance, before whiteness appears in the intellect. White depends on a thing (eg wall) for its existence, but it must be isolated from the wall to extract it's meaning, through the question, "what is whiteness"? Consequently, white comes first in the order of existence, but whiteness comes first in the order of intelligibility. The crucial question is therefore what comes first, what exists or it's signification? This is where Descartes turns his back to Aristotle, for whom the first question is "does this exist?" and the second is "what is this?". For Descartes like Plato, ideas are innate...
If you understand that whiteness is the fruit of your different experiences of white, the signification of whiteness and white are one and the same, on an abstract basis for the first and a concrete basis for the second. In parenthesis, the reason why placing the idea before the concrete reality is so tempting is because the abstract mode is pure (whiteness) whereas the concrete mode is impure (a white wall).
With regards to being, the transition from "this is" (judgement of existence) to "what is being?" is analogous to the transition from "this wall is white" to "what is whiteness?". In both cases, we move from the visible to the invisible. This adjustment seems almost innocuous, quite the contrary: either metaphysics connects with the radical structure of intelligence, or intelligence haughtily turns its back to it!