The Duality of Nature is the end-all of philosophy. It encompasses all our biggest questions, our morals, our ethics, how we live our lives. It can completely define the person. So lets take a peak.
What exactly is Duality? Ask 100 people and you'll get 100 different answers. For me, duality of nature, or duality of reality (nice ring to it) is the composition of all we know, divided into two parts;
1. The laws of the physical universe - those omnipotent equations that rule our matter and energy
2. The spiritual - the conscious experience we have, and the connection between life we can [sometimes] feel.
These two subjects are grand, and are quickly becoming some of the most important of our culture. Do we believe in life after death, do we believe that Science can prove all? Do morals matter? Heaven, God, Incarnation?
On the other hand, sometimes more relevant, is the duality of consciousness. It seems all things can be viewed as negative or positive (and different magnitudes thereof). On any given day you can wake up and feel absolutely ecstatic and a cup of coffee or the morning news will seem perfect, given the same circumstances your coffee could be difficult to put down and the news something so grim as to be shut off. The physical reality is the same, the experience is not. We can experience the positive or the negative. Here are the dualities of nature as far as I'm concerned.
So let me reiterate; I believe there are two types of duality, which are very closely related;
That between physical and spiritual, and that between negative and positive.
For the prior, my current belief is that no matter how much you believe in something, physical laws cannot be overcome - think about it. Imagine if someone believed so much that they could fly or that gravity didn't exist. The universe would break down - energy would come from no where, and things would become chaos - even from one person. The simple of act of creating a minuscule amount of energy from nothing would have disastrous implications. Related to this, I don't believe that science can ever deduce the spiritual - that is no matter how much we examine near-death experiences, no matter how hard we look for an after life or other spiritual beliefs we will never find them. In short; the physical and the spiritual don't mix - they are like oil and water. They both can exist, but they do not interact substantially.
For the latter - the duality of negative & positive - I believe you have complete control. It is a very well trained person that can take a bad event and create good, but I believe it is always possible. Some events, of course, are more healthy to view in a negative light, but I won't go there...
So how can one explain that spirituality and physical universe both exist without interacting? Well I believe that consciousness is tied to the spiritual, and the brain is absolutely physical. Somewhere in the brain is the answer, but again, deducing it would be impossible. It could be the simple fact that when electrons change energies or even orbit around the atom's nucleus they must "pop out" of existence - they literally aren't here anymore for periods of time and space. Maybe this disappearance is some sort of communication / information transfer to the spiritual? Who is to say?
I hope I have stirred some brain cells. Keep thinking, keep pondering, never forget curiosity.