'This will serve me a lesson,' said he, 'to look where I step. For if I should kill another bug or beetle I should surely cry again, and crying rusts my jaws so that I cannot speak.' Thereafter he walked very carefully, with his eyes on the road, and when he saw a tiny ant toiling by he would step over it, so as not to harm it. The Tin Woodman knew very well he had no heart, and therefore he took great care never to be cruel or unkind to anything.

'You people with hearts,' he said, 'have something to guide you, and need never do wrong; but I have no heart, and so I must be very careful. When Oz gives me a heart of course I needn't mind so much.'

The Wonderful Wizard of Oz L. Frank Baum

Let there be spaces in your togetherness, And let the winds of the heavens dance between you. Love one another but make not a bond of love: Let it rather be a moving sea between the shores of your souls. Fill each other’s cup but drink not from one cup. Give one another of your bread but eat not from the same loaf. Sing and dance together and be joyous, but let each one of you be alone, Even as the strings of a lute are alone though they quiver with the same music. Give your hearts, but not into each other’s keeping. For only the hand of Life can contain your hearts. And stand together, yet not too near together: For the pillars of the temple stand apart, And the oak tree and the cypress grow not in each other’s shadow.

Khalil Gibran (The Prophet)