I see you're lookong for an education... accepted I was trying to save it for the June 6th thing... but alas those who don't read need to be read to apparently.
Oh, on, second thought, I realize what error your having... because you understand that Nietzsche doesn't believe things exist solely in black and white dualism, that you think opposite ends of the spectrum don't exists. Hehe cute, though it's pretty poor logic to assume spectrums don't have opposite ends. And you have to also understand Nietzsche's use of the term "opposite" when he uses it means "the other end of the spectrum." Not a black and white 180...
So the second aphorism of Beyond Good and Evil literally starts off with a quote presented
by Nietzsche that mocks metaphysicsians (he literally gives it in quotes):
"How could something arise out of its opposite? For example, truth out of error? Or the will to truth out of the will to deception? Or selfless action out of self-seeking? Or the pure sunny look of the wise man out of greed? Origins like these are impossible. Anyone who dreams about them is a fool, in fact, something worse. Things of the highest value must have another origin peculiar to them. They cannot be derived from this ephemeral, seductive, deceptive, trivial world, from this confusion of madness and desire! Their basis must lie, by contrast, in the womb of being, in the immortal, in hidden gods, in 'the thing in itself'- their basis must lie there , and nowhere else!"
The next sentence informs upon the quote given by a typical metaphysician:
This way of shaping an opinion creates the typical prejudice which enables us to recognize once more the metaphysicians of all ages. This way of establishing value stands behind all their logical procedures.
Nietzsche writes that doubting whether something grows out of its opposite is a typical prejudice of metaphysicians... next Nietzsche talks about how they believe values exists in antithesis to each other rather than GROW out of their
OPPOSITE...
From this "belief" of theirs they wrestle with their "knowledge," with something which is finally, in all solemnity, christened "the truth." The fundamental belief of the metaphysicians is the belief in the opposition of values.
For example Good and Evil are antithesis with no bridging, where as Good and Bad, bad is the pale foil reflection of the good...from the opposite end of the spectrum (GoM10) like the Philosopher and his Shadow...
...skipping the middle unless you want me to go over it...
Now we can see Nietzsche putting at the fundamental base in which the true, genuine, unselfish grew out of is appearance, deception, self-interests, desire:
For all the value which the true, genuine, unselfish man may be entitled to, it might be possible that a higher and more fundamental value for everything in life must be ascribed to appearance, the will for deception, self-interest, and desire. It might even be possible that whatever creates the value of those fine and respected things exists in such a way that it is, in some duplicitous way, related to, tied to, intertwined with, perhaps even essentially the same as those undesirable, apparently contrasting things. Perhaps!- But who is willing to bother with such a dangerous Perhaps? For that we must really await the arrival of a new style of philosopher, the kind who has some different taste and inclination, the reverse of philosophers so far, in every sense, philosophers of the dangerous Perhaps. And speaking in all seriousness, I see such new philosophers arriving on the scene.
We can see Nietzsche suggesting there's a bridge of some kind connecting those "Good" values with the "Bad." Nothing bridges the antithesis of values...
If you want more aphorisms of Nietzsche detailing that which grows out of its opposite, lemme know, I'll drop em for you.