Let the force be with you, not against you

Stiff and unbending is the principle of death.
Gentle and yielding is the principle of life.
Thus an Army without flexibility never wins a battle.
A tree that is unbending is easily broken.
The hard and strong will fall.
The soft and weak will overcome.
--Lao-Tzu, Tào Té Chīng, Chapter 76, 6th century BCE

The "Chi" in T'ai Chi can be roughly translated as "ultimate," while the "T'ai" means "great." Originally, the practice of T'ai chi ch'uan developed strictly as a martial art, wherein "ch'uan" meant "fist," giving the art the full name of Great Ultimate Fist. But even as a martial art, T'ai chi ch'uan was a product of Taoist thought, having been developed (supposedly) by a Taoist monk in China--one Zhang Sanfeng--during the Song Dynasty, circa 960 to 1279 CE.

As such, it was--as a system--firmly grounded in Taoist principles: mastery proceeded necessarily from a calmness of spirit, mind, and body, and from constant practice as goal to be relentlessly pursued. And the application of force was always minimized, the goal was to absorb and use the force of others, either of things in the environment or of the opponent when in combat.