Lao Tzu, Chuang Tzu and others wrote about tao.
They observed the natural world and realised that there were distinct patterns and rules in operation.
These natural laws were too subtle to be rendered verbally, you had to intuit the way/how of them.

They realised that if you could sense the way of nature, you could move with it, rather than against it.
This offered the key principle of tai chi: yielding.