If we have purity of mind we create purity. In all we do, art, politics, business, music, industry, we pour out the purity of mind to such an extent even that those around us, strangers or friends, all have part in our joy. One says that diseases are infectious. But purity of mind is infectious too, and its effect creates purity in others. Some keep it for a long time, others keep it for a short time. It depends upon the mind.