As told by Grandmaster William Cheung:
Back when the Manchu's took over China, it took 18 years or more to train a full-fledged Shaolin martial artist. They had to do ten years of a hard physical style, and then eight years of internal style. During that time they also had to practice swords and spears, and various other kinds of weapons. So for the revolutionaries to train someone in Shaolin to match the skills of the Manchu soldiers, it would take 18 years ... and even then they were doing basically the same thing (with regard to fighting technique). They had to find a solution to this problem. So about 280 years ago, the oldest and most knowledgeable elders of the Shaolin Temple got together and decided to develop a style which would overcome all the other styles, and which would take a much shorter time to learn.
Then with that purpose in mind, they met repeatedly and engaged in lengthy discussions. Each elder was the master of his own style. And each master revealed all his secrets. Eventually, they developed a theory from which they derived a set of fighting principles.
The combat theory of the elders was as simple as it was profound. Since their objective was to invent a technically superior system of self defense, they began by examining the two existing types of martial arts. They noted that the hard or external styles - Shaolin, traditional chuan-fa, modern karate - committed the body's placement well before a kick or punch impacted with its target. In this way the technique accumulated maximum momentum, and imparted maximum force.
Of course the weakness of the approach was that the early commitment left the hard stylist vulnerable to an assortment of throws and perpetual unbalancing techniques. On the other hand, the soft or internal styles - tai chi chuan, pa kua, hsing-i - kept the body's weight elusive, and committed only at the instant of impact. But the problem with this approach was that the soft stylist did not strike with enough penetration or power.
The elders reasoned, then, that if they could devise techniques which landed repeatedly with both the unpredictable swiftness of a soft style and the violent penetration of a hard style, then no enemy would be able to plan an effective counter. All styles would be defeated. Consequently the monks agreed that the new fighting art should contain only those techniques which could be thrown with total commitment, halted abruptly, then instantly re-thrown from another angle with another committed technique.
They called their new approach the theory of interruption.
Next, since close-range techniques are both easier to interrupt and faster to learn, they determined that the new art would tend to emphasize in-fighting. Any attempts on the part of the enemy to use flashy, long-ranged movements such as high kicks and controlled swings, would be frustrated through a system of jams, straight-line hand strikes and quick, interrupted footwork patterns. The new stylist would be able to obtain favourable in-fighting distance safely, and with little effort.
Finally, once the proper in-fighting range was secured, the new stylist would have to be trained to use physical contact with the enemy's limbs to sense the enemy's next technique spontaneously. Then both hands could be used as a team for either interrupted strikes, combined with limb traps or for simultaneous parry-and-open hand with its slaps, grabs, parries, finger pokes and palm strikes, which would be favored over the closed fist.
This process of interruption would continue with increased fury until the enemy had been vanquished.
The Shaolin elders became so encouraged by the progress of their theoretical discussions that they renamed the martial arts training room in which they met "Wing Chun Hall" or "Forever Springtime" Hall. The words "Wing Chun" expressed their hopes for a renaissance in Shaolin martial arts instruction, as well as for a more effective weapon in their struggle against the Manchus. "But before they could completely develop their system," continues Grandmaster William Cheung, "someone tipped off the government and they raided the Shaolin temple. Everybody scattered."