This was a phrase coined by the Alchemist Dictum and often quoted by C.G. Jung. I must state that to the contrary there is a third option. It merely states that the 'third is not given' not that it doesn't exist. This is quite simply because it is for each of us to find individually. It is also not given because it is one of the great guarded secrets of Gnosticism. You give a lot of examples of the philosophy of duality. There are two ends of every spectrum, yes! But there is also a third position that is not given, it must be sought. This is triangle of completeness, the Holy Trinity, the center of the scale, the balance. It is literally the center point of all spectrum's. That which exist there, is the closest definition of God that can conceived. To attain this balance, is to become God-like, to achieve Gnosis!