The cause of duality is loneliness.

The cause of duality is desire. Yes. It is correct. Desire for what? Desire not to be alone. Desire for companionship. The cause of duality is loneliness; the purpose is Love aka Companionship. There is only Oneself desiring not to be alone. It is why Oneself sees itself as dual. Perhaps it can be useful when it comes to relationships, between men and women, countries too. What must be remembered at all times is that the purpose of Life is Love. Love is the only reason. Always return to Love. There is no other purpose but Love. Love equates to Companionship. It is the same.
~ Wald