Bruce Lee was considered by many in the Kung Fu tradition to be a heretic. In breaking from a commitment to a singular tradition, he formed Jeet Kune Do not as a new style, but a general epistemology to be open-minded to what works. Openness to all styles was a big no-no. Martial arts traditions, like religious traditions, have a history of promoting THE way (which was exclusively their way of course). It would turn out Lee was not a heretic, but a prophet, as modern mixed martial arts, by necessity, has heeded Lee’s advice to “absorb what is useful, discard what is useless and add what is specifically your own” . Beyond martial arts, there is a key broader philosophical gem that Lee offers us:
“Truth exists outside of all molds and patterns. Truth is never a set idea and definitely not a conclusion. The truth of life is a process.” 
There is an interesting parallel that can be drawn here to evolution. In contrast to “our way approaches it like this”, it becomes “let’s test and contrast these ideas through adversity and build a composite of the best features of all ways”. In this we find what works – the best of all ways is granted evolutionary fitness and survival advantage. Through natural selection and mutation, new tried and true forms emerge. This is the essence of adaptation.
To take it back to martial arts, as we saw in the early UFC, strikers that didn’t know grappling (Brazilian Jiu-Jitsu to be specific), would face inevitable doom. Then, as strikers started learning BJJ, “BJJ-only” martial artists had to evolve their game and incorporate striking. Today’s MMA artists have to be competent in both striking and grappling (at least, the successful ones). MMA has proven Lee is right. But if Lee’s epistemology holds true for martial arts, then it holds true for any intellectual or character endeavor.
Epistemological humility, open-mindedness, and the commitment to seek what is true and what works (vs. what is the accepted tradition or dogma) – this mindset allows for adaptability and fitness – and fuels the emergence of new forms emerge that are stronger and time tested. If, and this is a big if, we are willing to “be water”. In Lee’s words:
“Empty your mind, be formless, shapeless, like water. If you put water into a cup, it becomes the cup. You put water into a bottle and it becomes the bottle. You put it in a teapot it becomes the teapot. Now water can flow, or it can crash. Be water, my friend” 
In this, Jeet Kune Do is a mindset, not a “new way”, but a meta-way in which any way is considered and utilized, so long that it’s true and works. In his words,
“I have not invented a “new style,” composite, modified or otherwise that is set within distinct form as apart from “this” method or “that” method. On the contrary, I hope to free my followers from clinging to styles, patterns, or molds… Remember that Jeet Kune Do is merely a name used, a mirror in which to see “ourselves”. . . Jeet Kune Do is not an organized institution that one can be a member of… A Jeet Kune Do man who says Jeet Kune Do is exclusively Jeet Kune Do is simply not with it. He is still hung up on his self-closing resistance, in this case anchored down to reactionary pattern, and naturally is still bound by another modified pattern and can move within its limits. He has not digested the simple fact that truth exists outside all molds; pattern and awareness is never exclusive. Again let me remind you Jeet Kune Do is just a name used, a boat to get one across, and once across it is to be discarded and not to be carried on one’s back.” 
In the tribal, hateful, cancel-culture spirit we find ourselves in today, Lee’s epistemology is both brave and terrifying. Regularly putting our most cherished beliefs up to the test and deciding to be the best possible version of ourselves is far from comfortable. Just the opposite – getting uncomfortable, openness to other views, incorporating them, testing them, and clinging always to what is true above tribes and traditions – all allow our best ideas and selves to emerge and continue to adapt and strengthen.
It’s terrifyingly uncomfortable, but there are new forms, ideas, and character heights just waiting to be actualized – if we are willing.
Let’s be water friends.
 Lee, Bruce. Wisdom for the Way
 Lee, Bruce. Wisdom for the Way
 Lee, Bruce (September 1971), “Liberate Yourself From Classical Karate”, Black Belt Magazine, Rainbow Publications, Inc., vol. 9, no. 9, p. 24.