1+1= 1-every part is n the whole & the whole is n every part-Tao Te Ching-there is no life w/o death-no male w/o female-no light w/o dark-these r one in the same-glass half empty-glass half full-based on our 3 dimensional-5 sense perception we have to view opposites n order to exists...
Yep duality is pretty neat, two sides of the same coin. Light and dark, day and night, male and female, positive and negative, etc. The shadows are just as important as the light.