JKD is a “roadmap” of a territory. We need to follow it to some degree. Your experience within that territory is yours alone however.
The roadmap of JKD states that we must follow a certain path and to obtain knowledge of the territory (remembering that the map is not the territory).
Looking at the most important concepts (the "roadmap"):
*Simplicity: We have to make things simpler and not more complex. This means cutting through all unnecessary extrapolation and ornamentation. What does this means for us? Several things really. No more chi-sao. No more hubud. No more lop-sao/bong sao switch. No more high-outside reference point trapping. In fact, the only sensitivity drilling that we do anymore is clinch pummeling. Keeping things as simple as we can and stripping away what isn’t needed is a STAPLE of the JKD concept (daily decrease). Less is more, though you do have to keep what is necessary.
*Adaptability: The three core games (stand-up, clinch and ground). The four ranges are still there, but due to “simplifying” everything, we don’t give them “tool specific” names any longer. Kicking and punching ranges are still there, only now we refer to that as “stand-up”. The so-called trapping range is there, only now it’s referred to as the clinch. The ground we refer to as, “GROUND” (oddly enough). It’s not enough just to be a kicker, puncher, in-fighter or grappler. JKD implores that we strive to be ALL of those things (and notice how I did not say “karate guy”, kung-gu guy, Greco-Roman guy or jiu-jitsu guy. JKD is beyond style and sees only “tools”. That is a pretty important distinction, imo).
Having the quality of adaptability means that we can “float in totality”. We’re not limited. We can flow between ranges and “respond like an echo” to our opponent. We can meet whatever attack he may present because there is no unexplored territory for us (not being unfamiliar to any specific ‘line of attack’). We know what punches look like. We know what kicks look like. And underhooks, plumm positions, single legs, double legs, armbars, chokes, leg locks, etc., etc.
*Aliveness: Bruce Lee thought it was critical that we “get into the water” in order to experience swimming. This means, you gotta put the equipment on and fight. That is truly the only way you’re going to learn fighting. This doesn’t mean that you have to kill your partners. There are degrees of this for the sake of training purposes. We refer to this as progressive resistance and variable intensity. Progressive resistance means that you simply work up to higher levels of resistance. If you had never lifted weights before, I wouldn't put 500 pounds on the barbell and tell you to bench-press it. You'd start out light. However, if you never add more resistance than what you started with, you’ll never get stronger. So we must always progressively add.
Aliveness is also about realistic training practices. We need real timing even if we’re not using full power. We also need realistic motion as well. You can’t be standing in one place, flat-footed while practicing. You also need to not pull your punches, even if you’re not using full power. You have to try and hit your man, in the face, etc.
Now what the individual obtains through this practice, bearing in mind the above concepts, can never be taken from him. It is WON through hard work. Blood, sweat and tears. THAT becomes the individual expression of JKD. It’s NOT just taking anything and adding it “willy-nilly”, just to make that clear.