The Codes of Isshinryu

     1. A Person's heart is the same as heaven and earth.
     2. The blood circulating is similar to the moon and sun.
     3. The manner of drinking and spitting is either hard or soft.
     4. A person's unbalance is the same as a weight.
     5. The body should be able to change directions at any time.
     6. The time to strike is when the opportunity presents itself.
     7. The eye must see all sides.
     8. The ear must listen in all directions.

Explanation:

A Person's heart is the same as heaven and earth.
This code refers directly to harmony. In the martial arts, your body needs to know the techniques applicable to maintain harmony in your life. This means being able to defend yourself if necessary in order to restore peace. Most of the time if you feel confident in your abilities, the tranquility that you exhibit in difficult situations comes through and alleviates the need for escalation in physical conflict.

The blood circulating is similar to the moon and sun.
Just as the moon and the sun are in constant motion so should we as martial artists be in motion. We should not settle for the knowledge or abilities that we have but should always strive to continue to learn and progress. Perfection is a goal that we all try to attain but it takes continuous work and it is always just out of reach.

The manner of drinking and spitting is either hard or soft.
Situations that arise can be handled in a variety of ways. Conflicts can be taken care of through negotiations or with a physical response. Negotiations come in two varieties. The first is one where all parties walk away feeling like each has won. The second way is to give an ultimatum with a threat attached if something is not settled in a timely manner or with the desired results.
Even with physical responses, there are two possible scenarios. One in which the force used is only the amount necessary to convey to your opponent that it is wiser to submit because you have superior skills that could lead to their physical discomfort or worst. The other is to strike with so much force that the end result leaves little to the imagination.

A person's unbalance is the same as a weight.
Preparedness is essential in everything that we do in life. A martial artist needs to have the skill sets necessary to handle a variety of situations. Balance refers not only to the physical but also to the mental state. The skill sets required to be a good martial artist include being mentally prepared to handle situations that arise. The body and the mind need to act in unison to overcome any and all opponents.

The body should be able to change directions at any time.
Having a set or standard defense or offense is normal. However, life is not just black and white. Change is inevitable and you should be able to change whenever the situation warrants it. A defensive fighter prefers to let their opponent come to them just like an offensive fighter prefers to initiate the confrontation. Depending on the circumstances or the opponent, you should be able to adapt to the situation at hand. This means being able to change your tactics from defensive to offensive, linear to angular, or soft to hard.

The time to strike is when the opportunity presents itself.
Opportunities come up daily. Sometimes, they are veiled in a negative manner as in problems. Problems are things that come up and test our abilities to cope. Each problem as it is worked through gives us a new perspective on how to react, endure or solve a certain situation. We should take the good things that occur in our lives in stride and be grateful. Enjoy these times and take advantage of them. When life hits a sour note, work through the difficulty and don’t dwell on the negative. View everyday as a new opportunity to develop into a better person and martial artist.

The eye must see all sides. 
We live in a very visual world. Our reactions, whether positive or negative, are outcomes of what we see or to put it better what we think that we see. Most of our outlooks are based on the obvious. We need to look at things from all perspectives. This means not just through our own eyes but through the eyes of your opponent or adversary and through the eyes of someone outside the boundaries of the conflict. It is truly at that point that we see the whole picture and the solutions become clear.

The ear must listen in all directions.
Hearing is a valuable sense that is on automatically but is seldom used to its fullest capacity. Most problems or situations occur when we don’t pay enough attention to what we hear. In a confrontation we need to listen to what is being said, how it is being said and the tone of the voice. In a physical confrontation we need to listen to the breathing pattern, whether it is hard or soft. We need to listen to their movements whether they are stepping or sliding their feet. The more senses that we use in a conflict the better the decision making process becomes.