So to be more specific, the way I understand wing chun to be (at least the in the ideal way) is soft and hard.
I prefer to avoid the whole internal-external debate except to agree that WC has never been included with the classical
neijia systems, regardless of how soft the specific WC system may be, or even how much emphasis may be placed on chi-gung training.
The way of the WC I trained is definitely
soft, flexible and yielding. This can illustrated by our use of bong-sau. We try to make the whole body from feet, to trunk, to hand flexible like a spring. So if there is no obstacle barring your way, your stance, your body and your arm and fist spring forward to strike your opponent.
But if your opponent crosses your arm with stronger force, you allow your arm to receive the force and bend under the pressure like a supple wand of bamboo... Your opponent literally makes your defense with his energy...
He bends and flexes your arm into bong-sau (or tan-sau, etc. depending on the angle of the energy received). If your opponent advances with very powerful energy, he may also flex your torso and even your stance, causing you to slip aside in "turning stance". Then as your hand slips free, all that force your opponent has put into bending your arm and body is released and snaps back to strike him. Again think of a supple sapling being bent and released with a sharp
snap! This is our understanding of the famous kuit we translate as:
Stay with what comes, follow the retreat, and thrust forward when the hand is free.
Now the simple truth is that this is damn hard to pull off. For a strong, fast fighter, it is often easier to apply the techniques in a forceful, aggressive or "hard-style" fashion using straight-line attacks, delivered with economy, speed, and power to win the fight. And this is true with our students too. They get all hopped up in sparring and fall back on their aggressive instincts, using the same WC techniques, but in a forceful way. But the most skilled practitioners do manage to keep their cool and react using their opponent's force in the soft way I described.
Interestingly, I am just now beginning to understand how much that flexibility involves the shoulders, torso, and legs. My instructor is extremely elastic with his whole body... not at all with a "locked" waist the way
Hunt described. (No criticism against
Hunt here... I used to think that was the way my system was too!) It's just that some things were kept back, or maybe I was just too dense and now I'm finally getting it.