This is but saying that nothing can come from corn but corn, nothing from nettles but nettles.
Men understand this law in the natural world, and work with it, but few understand it in the mental and moral world, and they, therefore; do not cooperate with it.
Suffering is always the effect of wrong thought in some direction.
It is an indication that the individual is out of harmony with himself, with the Law of his being.
The sole and supreme use of suffering is to purify, to burn out all that is useless and impure.