In medieval times, gamekeepers trained dogs to the hunt by setting them on the trail of a dead rabbit they had dragged through the forest. Once the dogs were baying along the rabbit's scent, the gamekeeper ran across the trail ahead of them, dragging a gunny sack of red herrings. Red herrings are smoked fish that have been aged to a ruddy, stinking ripeness. If any dog veered off to follow the stench of the red herrings, the gamekeeper beat him with a stick. Thus did dogs learn not to be lured into barking up the wrong tree.
This practice became the namesake of one of the best-known types of fallacies, the red herring fallacy. As a philosophy professor, this is how I explain the fallacy to my students: If the argument is not going your opponent's way, a common strategy — though a fallacious and dishonorable one — is to divert attention from the real issue by raising an issue that is only tangentially related to the first.
