As long as the tears represent a genuine release of emotion, they should be permitted to fall. But crying quickly changes from inner sobbing to an exterior weapon. It becomes a tool of protest to punish the enemy. Real crying usually lasts two minutes or less, but may continue for five. After that point, the child is merely complaining, and the change can be recognized in the tone and intensity of his voice. I would require him to stop the protest crying, usually by offering him a little more of whatever caused the original tears. In less antagonistic moments the crying can easily be stopped by getting the child interested in something else.