Fifthly, many evils depend upon precisely what laws the world contains. An omnipotent being could, for example, easily create a world with the same laws of physics as our world, but with slightly different laws linking neurophysiological states with qualities of experiences, so that extremely intense pains either did not arise, or could be turned off by the sufferer when they served no purpose. Or additional physical laws of a rather specialized sort could be introduced that would either cause very harmful viruses to self-destruct, or prevent a virus such as the avian flu virus from evolving into an air-born form that has the capacity to kill hundreds of million people.