Meeting Hardness with Softness
Tai chi practitioners learn to avoid directly fighting or resisting an incoming force. Instead, they want to meet it in softness and follow its motion while remaining in contact.
This allows one to wait until the incoming force of attack exhausts itself. The approach of softness can safely redirect the incoming force.
When done correctly, this creates balance in combat and in dealings with others and nature. In a broader philosophical sense, finding balance is a primary goal of tai chi training.