I'd like to throw in some logic from the Diamond Sutra (hope that's OK!) to this "General Philosophy" discussion.
X doesn't have any nature of X... in this way we call it X.
I.e., "down" is never really down, so that is why we make sure to call it "down."
Dukkha is never fixed as a dukkha. That is why it is called "dukkha."
In "self," there is no self which can be seen; it is in that way that the Tathagata calls it "self."
What do you guys think?