A tree that is unbending is easily broken.
"A man is born gentle and weak. At his death he is hard and stiff. Green plants are tender and filled with sap. At their death they are withered and dry. Therefore the stiff and unbending is the disciple of death. The gentle and yielding is the disciple of life. A tree that is unbending is easily broken. The hard and stiff will be broken. The weak and supple will prevail." - Lao Tzu Tao Te Ching - chapter 76