Niju Kun ( )
Funakoshi also wrote 20 additional principles, known as, Niju Kun ( ) , which are the subset of the Dojo Kun( 道場訓 ) .  Niju Kun ( ) includes training principles and moral principles for the student to abide by.  
  1. Do not forget that karate begins with a bow and ends with bow.
  2. In karate there is no first attack.
  3. One who practices karate must follow the way of justice.
  4. Know yourself first, then you can know others.
  5. Spirit and mind are more important than technique.
  6. Be ready to release your mind.
  7. Misfortune comes out of idleness.
  8. Don’t think that what you learn in karate can’t be used outside the dojo.
  9. It will take all of your life to learn karate.
  10. Put karate into your everyday living; that is how to see its true beauty.
  11. Karate is just like water; if you do not give it continuous heat, it will become cold.
  12. Do not cling to the idea of winning; it is the idea of not losing that is necessary.
  13. Move according to your opponent.
  14. In conflict, you must discern the vulnerable from the invulnerable points.
  15. Consider your opponent’s legs and arms as you would lethal weapons.
  16. Be aware at all times that you have millions of potential opponents.
  17. Postured stance is for beginners; later comes naturalness.
  18. Kata is about correct and proper form; engaging in a fight is something else.
  19. Do not forget: 1) strength and weakness of power; 2) contraction and expansion of body; and 3) rhythm of techniques.
  20. Always create and devise. 
Karate ni sente nashi ( 空手に先手なし)
Of all the precepts in Funakoshi’s Niju Kun ( ) , the most often paraphrased is, “Karate ni sente nashi ( 空手に先手なし ),” translated meaning, “Karate has no offense.”  It is also the most misinterpreted and misunderstood phrase. Some have literally interpreted as, there are no offensive techniques in karate - only defense.  Others have interpreted as one should not strike first when attacked, leading them to believe is the reason why the first movement in all kata ( ) begins with a block.  
The underlying meaning of this precept is never to use karate for ill intention or resorting to violence as the first or only solution.  First, never provoke a fight or be in a position of danger.  How to stop or avoid the danger becomes the response to “Karate ni sente nashi( 空手に先手なし ) .”  In a violent confrontation, human beings revert to their animal instinct and their senses are heightened.  If the danger is imminent, the karate-ka can diffuse the attack with their own action – be it block and countering or taking the initiative to strike first.  To allow the assailant to execute the first strike before countering could be detrimental to one’s safety or others.  Most people think of self-defense as protecting only themselves.  There may be instances where loved ones are involved.  If the assailant attempts to strike a loved one first, such as a child, chances are the guardian will not allow the first blow to hit the child. 
Karate ni sente nashi ( 空手に先手なし ) is another way of reminding karate-do students to refrain from violent behavior, and not to initiate a fight, physically or verbally.
Budo Aspect
“In true Budo, there are no opponents.  In true Budo we seek to be one with all things, to return to the heart of creation.  In real budo, there are no real enemies.  Real Budo is a function of love.  The way of a warrior is not to destroy and kill but to foster life, to continually create.  Love is the divinity that can really protect us.”  Ueshiba Morihei, Founder of Aikido
A young student traveled to Japan to a famous martial art school and had an audience with the sensei. 
“Sensei,” asked the student, politely, “I wish to become your student.”  He then proceeded to ask, “how long will it take to become a black belt?’
“Ten years at least” replied the sensei.
“Ten years is a long time.  What if I study twice as hard as the other students?  How long will it take then?” asked the student.
“Twenty years,” responded the sensei.
“Twenty years!  What if I study day and night, how long will it take?” said the student.
“Thirty years” sensei responded.
“How is it that every time I say I will train harder; you tell me it will take longer?” asked the puzzled student.
“The answer is easy.  When one eye is fixed on the destination, there is only one eye left to find the Way.” Said the sensei.
The word “do ” or “Tao” in Chinese, is simply defined as, “the Way.”  Anyone with some familiarity of Chinese or Japanese kanji will recognize the character for “do ” to have two meanings, “road” and “way.”  However, the exact meaning of “do ” or “Tao” is ineffable in English, which is beyond the scope of this book. The more pragmatic interpretation, used by the Japanese to mean, “the Way” eludes to the act of seeking the path while studying an art form. Thus, many of the Japanese martial arts have the “do ” associated with the art, such as, Budo( 武道 ) , Judo, Aikido ( 合氣道 ) , Kyudo( 弓道 ) , Kendo ( 剣道 ) , and Iaido ( 居合道 ) , to name a few.  The use of “do ” is not strictly for martial arts as many other Japanese art forms are also associated with the use of do :  Chado ( 茶道 ) (tea ceremony), Kado( 華道 ) (flower arrangement), and Shodo (書道 ) (calligraphy), as a few examples.  The inference of using “do ” with each of the art is to suggest a lifetime of commitment is to be made to studying the art.  
More than just studying the art, “do ” is about living it in our daily life, as the sensei’s response to the eager student suggests in the above parable.  When a student is fixated on only achieving a particular goal in the art, he is not experiencing it in his daily life, hence will require more time to understand and realize the “do ” aspect of the art.  An analogous example is of a student who is all consumed in obtaining a college degree in an academic subject and neglects social interaction with others.  By studying harder than anyone else to achieve the goal in a shorter time, he or she would have missed the life lessons that college had to offer.  Once removed from the academia life, the student’s ability to interact with others socially becomes perhaps awkward, not necessarily in the characterization of an introvert versus extrovert, but like the cliché; “all work and no play makes Jack a dull boy.” Simplistic example in relationship to “do ,” but the point of walking “the Way” is to experience all that one encounters throughout the process.          
Prior to the use of “do ,” “jutsu ( ) ,” meaning “art” was used as the suffix after each martial art, e.g. Bu-jutsu, Ju-jutsu, Aiki-jutsu, etc. The distinction between “do ” and “jutsu ( ) ” is often misunderstood and interpreted to be the same. Jutsu ( ) , being the predecessor to “do ,” became the method for developing martial skills to win in combat. But “do ” meant something greater than winning or losing for the practitioner – it is a way to enrich one’s life through the rigors of physical and mental training.  Jutsu is not discarded for the sake of “do ” but rather enhanced to provide a means for the student to reach a higher level of wisdom.  This is not to imply “do ” to be better than “jutsu ( ) ” or vice versa.  In fact, some masters prefer to retain the jutsu ( ) suffix in order to maintain the pure martial elements of the art, as in the case of Ju-jutsu and some Aiki-jutsu. But the use of “do ” suggests a martial art to have evolved from a total combat form to one that seeks to perfect an individual’s character for seeking peace and wisdom.      
In seeking this “Way” of developing one’s character, it is important to note the reference of “do ” when referring to the place of studying the art called, dojo.  Dojo is commonly translated as, training hall or place of training a particular martial art.  But the significance of “do ” should be understood to mean the place to train “the Way.” Even the uniform, commonly referred to as, “gi ,” is properly named, do-gi( 道着 ) to make the distinction of wearing something unique when pursuing the study of “do .”  Whether the omission of “do ” in gi , and likewise in casual referencing of karate, is purely for the sake of simplicity or naiveté, the importance of studying “do ” must be understood as part of art, where proper attire, place of training, and proper etiquette should be observed.  Those who fail to understand the practice of “do ” will not bother to keep the dojo or their do-gi ( 道着 ) clean.  Karate-do of course, can be practiced anywhere with any type of garment, but when training in the dojo, proper manners and etiquette are practice so that the student can extend this behavior outside the dojo.  The importance of training in the dojo is emphasized by Okinawan karate-do master, Nagamine Shoshin:
“The dojo is a place where courage is fostered and superior human nature is bred through the ecstasy of sweating in hard work.  It is the sacred place where the human spirit is polished.
Traditional Japanese martial arts all fall under the umbrella of Budo ( 武道 ) , which in English is translated to simply mean, “Martial Way,” which is usually conceived to be war-like.  The Chinese character or Japanese kanji for “Bu ” is a combined ideogram to mean, ‘stop’ and ‘halberd,’ referencing a weapon.  While “Martial Way” explicitly refers to method of war or fighting, the ideogram for “Bu ” is implicitly understood to mean, ‘stop a weapon.’  Budo ( 武道 ) , therefore, becomes a method of seeking ways to prevent or stop the use of a weapon or fighting.  The simplistic definition of “Martial way” lends itself to viewing Budo( 武道 ) only from one perspective – way of fighting.  The more profound view of Budo( 武道 ) is to enrich the practitioner’s life, in terms of health, mind and knowledge, preventing violence, and forging a person with moral values. 
When budo ( 武道 ) or bujutsu ( 武術 ) is mentioned, most naïve karate-ka these days would reference the samurai warrior, believing they must train with the same intrepid attitude of kill or be killed.  Certainly, karate-do training forges an indomitable spirit within the practitioner, but it is not only this aspect that defines a samurai.  While the mention of a samurai is associated with courage and relentless spirit, many do not realize that the title of samurai itself is one of servitude, which elevates them above the status of a warrior.  As a servant and protector to a lord, a samurai is bound by duty and the code of Bushido ( 武士 ) (translated as, military knight way, or ‘way of the warrior’).  The code of Bushido (武士道 ) has the same chivalrous character for the samurai as the Code of Chivalry required of the, often romanticized, knights of medieval times.  Even though it may be hard to find such chivalrous behavior today, the budo ( 武道 ) aspect of martial arts continues to promote the valuable characteristics outlined in the code of bushido ( 武士道 ) : honor, sincerity, veracity, loyalty, and benevolence.  The misguided thought is that karate-ka trains with the same code as the samurai, which is incorrectly relating the code of bushido( 武士道 ) to budo( 武道 ) .  Bushido ( 武士道 ) refers to the way of the samurai, with the intent to kill and to commit seppuku, ritual suicide, if necessary, to retain honor.  Budo ( 武道 ) , on the other hand, implies martial arts being practiced preserving life and to bring about peaceful coexistence for the martial artist.  To simply state that one trains like a samurai warrior is to incorrectly ignore the more important qualities that is defined by the practice of budo( 武道 ) ; a person with integrity and honor.     
Understanding budo ( 武道 ) is not only about possessing a skill but also about shedding that which is unwanted in a human trait.  True testament of budo ( 武道 ) was displayed during one of the most unforeseen karate demonstrations by a highly skilled karate-do sensei.  At the height of karate’s popularity in the United States during the 1960’s and 1970’s, demonstration from the great Japanese masters became highlights of tournaments.  Many such demonstrations were executed with such precision that would leave the audiences in awe.  But the one demonstration that stunned the crowd had less to do with the awesome technical skills of the master, as much as the outcome of the demonstration.  The following is an account of the infamous demonstration by Nishiyama Hidetaka Sensei.
Nishiyama Sensei performed the kata called, Hangetsu, with such intensity that left the audience wanting to see more.  After the solo performance, he demonstrated the application of the kata with multiple attackers from various directions.  To make the application even more intense, the attackers were armed with knives and clubs.  As if in a Zen state, Nishiyama went through his motions adeptly eliminating one attacker after another.  In the processes of disarming one of the would-be attackers wielding a knife, Nishiyama struck the knife out of the hand of the demonstrating partner, which landed in a precarious position.  When the attacker was swept off his feet, Nishiyama realized the potential danger to the demonstrator if he landed on the dangerous knife, held the demonstrator and stopped the flow of his demonstration.  The rhythm of the demo had now been disrupted, allowing the other attackers with clubs to descend upon the great Japanese Sensei.  In a state of dismay, the two attackers were shocked that Sensei had left himself so open to the attack, which was rehearsed without error in the dojo.  When they realized what Nishiyama Sensei had done to prevent a potentially dangerous outcome for the other attacker, the demonstrators bowed to Nishiyama Sensei and ended the demonstration. 
To the audience, the demonstration ended abruptly with what would be considered less than perfect execution by a great karate master.  At that moment, the bewildered audience had no idea what had transpired, other than witnessing a demonstration that was flawed.  But to the demonstrators and some karate-ka in the audience, they had just witnessed a great Sensei who had displayed the true meaning of budo ( 武道 ) .  Nishiyama Sensei knowing he would be exposed to being attacked by the clubs, had sacrificed his own demonstration to save the knife wielding attacker from injury.  The audience would have certainly glorified his outstanding skills had he proceeded in completing the demonstration with no regards for the safety of the knife welding student. By saving the student from potential harm, Nishiyama Sensei had shed his ego for the safety of another human being.
“To work on learning is to increase day by day; to work on Tao is to decrease day by day.”   Tao Te Ching.
If budo( 武道 ) is perceived to be only a martial method of defeating an opponent, then other forms of “do ” arts are relegated to only the defined discipline, e.g. Chado ( 茶道 ) , only for serving tea, or Kado( 華道 ) , only for flower arrangement.  All the “do ” arts seek the truth and understanding through their respective art form. The idea of following the “do ” is to elevate the individual in their respective discipline from which they learn to become a better person.  And in turn the individual is able to better serve society.   The extension of these “do ” art forms is embedded into the culture of Japanese society as part of “Wa,” meaning harmony, and integral to the understanding of the arts.  The martial spirit aspect of budo ( 武道 ) is part of karate-do training, just as much as the refined skills required to make and serve tea is part of Chado ( 茶道 ) . But the true understanding of budo ( 武道 ) is about living life in harmony through practicing the arts. 
To the uninformed karate-ka, the casual use of the term budo ( 武道 ) is simply for expressing the martial spirit.  The interpretation of “bu ” to stop a weapon becomes mainly about the ability to stop the opponent’s weapon by fighting.  And the cry for “budo ( 武道 ) spirit” is to invoke an indomitable fighting spirit to defeat the opponent.  Such narrow-minded thought process is to limit the skill of the karate-ka to focus purely on fighting skills.  A tiger has more fighting spirit than any human being.  But the tiger does not possess the skill level or the wisdom to control their action.  The drive for more “spirit” is to encourage the karate-ka to push through with unrelenting effort and overcome their physical limitation.  The application of “budo ( 武道 ) spirit” goes beyond the ability to fight.  The true mastery of budo( 武道 ) is controlling the outcome.  
One of the revealing demonstrations of budo ( 武道 ) in action was witnessed by Kano Jigoro, Founder of Judo.  When Kano first witnessed Ueshiba Morihei’s (Founder of Aikido) demonstration of aikido ( 合氣道 ) he remarked, “This is ideal Budo( 武道 ) .”  Ueshiba’s fluid motions dispatched his would-be attackers with ease, without causing harm as each of the attackers were thrown to the ground.  Often Ueshiba’s demonstrations would have multiple opponents attacking from various directions both sequentially and simultaneously.  Ueshiba had not only mastered the technical skills of his art but was able to demonstrate the essence of budo ( 武道 ) – controlling and harmonizing with the opponents’ actions. 
“Three essential elements of budo are; the timing of heaven, the utility of earth, and the harmonization of human beings.” Koden Bugei
“All things have an inner divine essence and an outer marvelous function.  The essence of a tree is manifested in its wonderful blossom and abundant foliage.  The essence of tree could not be perceived if there were no blossom and leaves.  Human beings have an inner divine essence that cannot be seen but is manifested as the marvelous techniques of budo.”   Heiho Jinkansho, Kajima Shinto School