Polarities....

Everything comes in pairs as death with life and darkness with
light. Whatever seems to be necessary to existence is so only because
its opposite is equally necessary. Duality is a governing factor of
the world and everything within it including ourselves. That alone is
outside the world, is nondual, which is the untouchable Reality. This
is the Chinese idea of yin and yang, and the Bhagavad Gita's
expression "the pairs of opposites" conveys the same idea. Duality is
a fact. It is here. But it is also an illusion and the opposite truth
which completes it is the nondual. We may deplore the illusory nature
of our existence, but we need not get lost in it for it is fulfilled,
completed, and finalized in its complement the Real.

— Notebooks Category 26: World-Idea