Bruce Lee stated that his concept is not an "adding to" of more and more things on top of each other to form a system, but rather, a winnowing out.
The metaphor Lee borrowed from Chan Buddhism was of constantly filling a cup with water, and then emptying it, used for describing Lee's philosophy of "casting off what is useless".
He also used the sculptor's mentality of beginning with a lump of clay and hacking away at the "unessentials"; the end result was what he considered to be the bare combat essentials, or JKD.
The core concepts of JKD are derived from Wing Chun. This includes such ideas as centerline control, punching with a vertical fist, trapping, and forward pressure.
Through his personal research and readings, Lee also incorporated ideas from boxing and fencing.
Later during the development of Jeet Kune Do, he would expand to include the art for personal development, not just to become a better fighter.
To illustrate Lee's views, in a 1971 Black Belt Magazine article, Lee said "Let it be understood once and for all that I have NOT invented a new style, composite or modification.
I have in no way set Jeet Kune Do within a distinct form governed by laws that distinguish it from 'this' style or 'that' method.
On the contrary, I hope to free my comrades from bondage to styles, patterns and doctrines."
One of the theories of JKD is that a fighter should do whatever is necessary to defend himself, regardless of where the techniques come from.
One of Lee's goals in Jeet Kune Do was to break down what he claimed were limiting factors in traditional martial arts training, and seek a fighting thesis which he believed could only be found within the reality of a fight. Jeet Kune Do is currently seen as the genesis of the modern state of hybrid martial arts.
Jeet Kune Do not only advocates the combination of aspects of different styles, it also can change many of those aspects that it adopts to suit the abilities of the practitioner.
Additionally, JKD advocates that any practitioner be allowed to interpret techniques for themselves, and change them for their own purposes. For example,
Lee almost always chose to put his power hand in the "lead," with his weaker hand back; within this stance he used elements of boxing, fencing and Wing Chun. Just like fencing, he labeled this position the "On Guard" position.
Lee incorporated this position into his JKD as he felt it provided the best overall mobility.
He felt that the dominant or strongest hand should be in the lead because it would perform a greater percentage of the work. Lee minimized the use of other stances except when circumstances warranted such actions.
Although the On-Guard position is a good overall stance, it is by no means the only one. He acknowledged that there were times when other positions should be utilized.
Lee felt the dynamic property of JKD was what enabled its practitioners to adapt to the constant changes and fluctuations of live combat.
He believed that these decisions should be done within the context of "real combat" and/or "all out sparring" and that it was only in this environment that a person could actually deem a technique worthy of adoption.
Bruce Lee did not stress the memorization of solo training forms or "Kata", as most traditional styles do in their beginning-level training.
He often compared doing forms without an opponent to attempting to learn to swim on dry land. Lee believed that real combat was alive and dynamic.
Circumstances in a fight change from millisecond to millisecond, and thus pre-arranged patterns and techniques are not adequate in dealing with such a changing situation.
As an anecdote to this thinking, Lee once wrote an epitaph which read: 'In memory of a once fluid man, crammed and distorted by the classical mess.
' The "classical mess" in this instance was what Lee thought of classical martial arts.
Bruce Lee's comments and methods were seen as controversial by many in his time, and still are today. Many teachers from traditional schools disagreed with his opinions on these issues.
The notion of cross-training in Jeet Kune Do is similar to the practice of mixed martial arts (MMA).
Many consider Jeet Kune Do to be the precursor of MMA because of its syncretic nature. This is particularly the case with respect to the JKD "Combat Ranges".
A JKD student is expected to learn various combat systems within each combat range, and thus to be effective in all of them.
