Joy and sorrow both are for each other. If it were not for joy, sorrow could not be; and if it were not for sorrow, joy could not be experienced.

If there was no pain one would not enjoy the experience of joy. It is pain which helps one to experience joy. Everything is distinguished by its opposite. The one who feels pain deeply is more capable of experiencing joy. And personally, if you were to ask me about pain, I should say that if there was no pain life would be most uninteresting to me. For it is by pain the heart is penetrated, and the sensation of pain is deeper joy. Without pain the great musicians and poets and dreamers and thinkers would not have reached that stage which they reached and from which moved the world. If they always had joy, they would not have touched the depths of life.

There is the sun and there is the moon, there is man and woman, there is night and there is day. The colors are distinguished by their variety and so are the forms. Therefore to distinguish anything there must be its opposite; where there is no opposite we cannot distinguish. There must be health in order to distinguish illness; if there were no health and only illness then it would not have been (distinguished as) illness. ... Life is a puzzle of duality. The pairs of opposites keep us in an illusion and make us think, 'This is this, and that is that'. At the same time by throwing a greater light upon things we shall find in the end that they are quite different from what we had thought.