Stains grow and spread by the law of accretion through attraction, meaning that similar substances are drawn to each other, and bond together as one. To see this law at work -- even in our own coffee cup -- is to see all negative thoughts and feelings for what they are: a source of foulness that, if left to breed in the darkness of an unattended mind, becomes a stain that first soils, and then spoils the life of our Soul.