11. Tai Chi Ch'uan, the performance of physical exercises to induce and direct energy flows within the body to gain mastery of body, breath, mind, the internal organs, and life and death.

Tai chi is a method to harmonize the polarity of elements in life it is a way to perceive the relativity of things to realize that any phenomenon can never be manifested without the opposing counterpart, that is illusory to take one side, the Yes can’t exist without the No, you can’t reject completely the No since is part of the equation, they are not in opposition they are two sides of the coin inseparable. 
Tai Chi is the representation of the ultimate balance between hard and soft, male-female, right and left, manifesting and hiding, life and death, universal and personal, real and unreal, possible and impossible all the antagonism in harmony without any intention to destroys any opposite, it is able to use wisely the forces that we possess at the right time without any attachment. It is imitating nature at the most primitive scale at the most microscopic proportion when is only yin and yang.
Tai Chi Chuan  brings the concepts of yin and Yang to a practical application to use the principles to guide your energy to avoid correctable imbalances to prevent unnecessary waste of Chi, the energy is neutral can go up or down, hate is no other thing that loves doing headstand, chi can be used to heal or to fight.
There are many layers of learning; imaging the operating system in your computer after installing it you might need some software, so the first part are the forms or Katas or your operating system, doesn’t matter what style of Tai chi Chuan they have similar operating systems and also programs.
 They all use the vital energy or Chi is what maintains the rivers or meridians flowing, the power of the punch is not the manifestation of your muscular contraction or speed, but the conduction of all your energy with no fragmentation at one particular point in a nanosecond. If all your muscles could pull in one direction, you could create a force of 25 tons and if these relax muscles are carrying the detonator of chi that exploits at contact your force will be tremendous.
In  order to be skillful you have to follow nature and the skills that nature gave us,the first step is to understand how nature function in us, the left side of your brain controls de right side of your body and vice versa so the opposite shoulder should coordinate with opposite hip, elbows with knees and hands with feet without this step you can't progress.
At the same time you coordinate the entire right or left side of your body, the speed in the changes determine your competence but like a paradox is primordial to practice slowly because you want to change the Neuro-patterns but first you need to change the Neurotransmitters so you can move fast in control, but you can move fast and have no force, the muscles have to move from liquid to solid at the impact's point and after liquid again.
You can not do this controlling the breath so teachers never give instructions of how to breathe but meditate in vipassana observing the breath after years of practice the breath become essential to progress and help you to exert force. as the waves of the ocean, you move forward and back. So the director is the lower Dan-Tien he is multi-task and can not only act as the orchestra director but can perceive the state of affairs of your opponent and highjack his center.
We are all egotistic we have to survive in a situation of life and death your brain stops working the blood move from the brain to your guts, triggering a chain of hormones that produce the flight-fight respond mechanism of defense you will get speed and force that we don't ordinarily use because the situation is extremely extraordinary, those movements, if they are not rehearsed, becomes chaotic, uncoordinated leaving for your opponent with better center a lot of options to attack.
So you train the mind to accept the chaos and try to don't use your own force but following a path of less resistance redirecting it, not getting too anxious and wait for the right opening, not allowing the glands to take command; in a normal training without the opponent in front you might be able to observe the enemies of the mind, the chain of negative thoughts that unfortunately is the majority of our thoughts, and have the skills to divert them as you divert the opponents attack.
The ultimate skills in Tai chi chuan is to accept the other side of survival is not easy to maintain calm confronting an enemy with a sword, so acceptance of death is the other part of the skills, to be honest to your training reacting exactly the same doesn't matter the object, so who can't we be completely sure that we have another day, the acceptance of death is life the  denying of death is death.
For me Tai Chi Chuan is overall the most sophisticated of all the corporeal expressions, some people are not to wrong pairing Taichi Chuan with dancing, of course, is graceful and looks like dancing but there is no story to say, there is no emotional connotation, it is not sexual, or remembering glorious events of the past, or asking for a good harvest, you want to move in coordination like the planets move with orbits and circles like this marvelous universe moves.

You need time to add more and more connections between you and the universe so the older you get the better you do your practice that is not similar to other physical activities, your practice is like a good wine you can be confident even at a very old age, there many things or operating systems to install, the movement of your chi through your channels, the coiling action than everything has in this universe, the soft and hard of each pose, the metaphysical allegory that every pose has, the organs,  the Dantiens and with precision the location of everything that you do, after the house is in order; the connection of the organs with the planets, being your center the northern star and the 28 constellations so when you leave you to know the way to get back home.