A question that comes up a lot from beginners seems to be “what defines Tai Chi Chuan?”. Non-beginners seem to not worry about this question and just practice, which is for the best, but it seems everybody goes through a stage where their mind needs to define and categorise what it is they’re doing. What makes it Tai Chi Chuan, as opposed to, say, Bagua, or JuJitsu?
I can only answer from my current understanding. I’ve been doing Tai Chi long enough to realise that today’s epiphany is tomorrow’s half-truth, so I wouldn’t say this will be my final word on the subject, but it’s something I’ve settled on recently.
When defining what Tai Chi Chuan is I look first at the name – TaiChi boxing/fist. So, it’s a martial art whose chief feature is about TaiChi – the interaction of Yin and Yang. Therefore, for a movement to be Tai Chi Chuan it requires that the interaction of yin and yang is correctly distinguished (i.e. in harmony) in all the movements, and (crucially) also in the fighting strategy (no double-weighting).
On one level my answer sounds like a ridiculous over simplification, and it is, but that doesn’t make it ring any less true. It’s only when you ask yourself ‘what does distinguishing yin and yang mean?’ that you realise how deep the wormhole goes. There are obvious, simple, answers like always having your weight on one leg and not both at the same time, but there are much more subtle answers to do with where force is inside the body, and how it is utilised.
A good place to start with this line of enquiry is by looking at your own form with No.4 of Yang Cheng-Fu’s 10 Important Points in mind.
4.) Differentiate between insubstantial and substantial. This is the first principle in T’ai Chi Ch’uan. If the weight of the whole body is resting on the right leg, then the right leg is substantial and the left leg is insubstantial, and vice versa. When you can separate substantial and insubstantial, you can turn lightly without using strength. If you cannot separate, the step is heavy and slow. The stance is not firm and can be easily thrown of balance.