A modern definition of self-defense is in order. Personal self-defense is not warfare; it is not vengeance; it is not an art; it is not a sporting event; it is not a movie or television fight scene.
Self-defense is preparation to minimize the possibility of assault. It is training to learn and use appropriate and effective physical actions if there is no practical available alternative.
Self-defense instruction is the beginning of a process of learning how to avoid becoming a victim. Many victims of assault are victims not because they lack the capacity to win fights but because they have been given absolutely no preparation to cope with this special kind of emergency.
The old-fashioned view that self-defense instruction is training to reach a high level of fighting skill has the effect of eliminating those individuals who have the greatest need. It is precisely those people who are unable or unwilling to become fierce fighting machines who benefit from practical self-defense instruction to the greatest degree.
People learning to defend themselves against assault ought not to be trained as though they were preparing for warfare. The concepts, techniques and methods appropriate for training Samurai warriors are not those appropriate for teaching self-defense as a practical skill for today.
The legal and moral definition of self-defense expressly limits the degree of force to the least which can be used to avert, stop, or escape from an intended assault. In old-style self-defense, every assault is viewed as a very vicious assault. Real life is different. There are degrees of danger. Assault intentions range from mildly threatening to the intent to do great bodily harm. More important, there are mildly threatening situations which, if handled properly with assertive self-control, can be prevented from escalating into physical violence.