Fundamental Principles of Judo by Kenji Tomiki

Fundamental Principles of Judo
by Kenji Tomiki

uki otoshi

Kenji Tomiki was born March 15, 1900. In 1956 when the following was first published, Kenji Tomiki was 7th dan Judo, 8th dan Aikido, Professor of Judo at Waseda University, a member of the Kodokan's Special Direction Committee, and an official of the All Japan Judo Federation. In 1971 he was awarded the 8th dan in Kodokan Judo. Kenji Tomiki died December 25, 1979.

Table of Contents

1. Physical Training
Shizentai (natural posture)
Sen (initiative)
Kuzushi (breaking balance)
Ju-no-ri (principle of gentleness)

Judo as Physical Training

It is a fundamental principle of sports to carry on exercises in proportion to the bodily strength. Judo as a game belongs to the fighting games and so often assumes all the aspects of an intensive feat of strength requiring strenuous exertions. In the practice of Judo, however, this evil can be averted by means of Kata (forms). That is, the kata enables the Judo student to adjust the amount of exercise according to his bodily strength and age, and yet is fully effectual both in respect to interest and benefit.

Judo includes the following three points in its objective on the physical side:

  1. Toughness (giving steadiness, elasticity and staying power to the muscles)
  2. Flexibility (giving mobility to the spinal column and other joints together with full elasticity of the muscles)
  3. Adroitness (quickening the function of the motor nerves and making movements both nimble and steady)

From the standpoint of athletic physiology these qualities are correlated with one another, and the bodily activities in Judo exercises are best adapted to those requirements.


The shizentai, or natural posture, is the posture of a person standing quietly with his head and upper body kept upright, arms hanging without constraint and legs not so firm and widely apart. This is the description of the proper posture as regards its form, but it has a deeper, wider significance. When this posture is maintained, it may be considered that 1) the body keeps stability and does not fall and 2)as the limbs are kept soft they can shift to any action at any moment.

In the preceding paragraph the natural posture is explained as a standing posture. If, however, outward form or posture is left out of consideration, and the natural posture is an attitude of the body which is capable of repelling the opponent's attack, and moreover of assuming the offensive whenever there is an opening in the opponent's guard, the natural posture may be said to be possible not only when standing, but also when sitting or lying. In fact, in a Judo contest, the contestant who has fallen is not nedessarily beaten. On the contrary, he may make an attack against his opponent while lying on the mats. In fact, the natural posture is an attitude of the body which is always capable of taking the lead.

There is an old expression, "Motion in rest." It means that rest is pregnant with motion as infinite activity, so it indicates the principle of natural posture. Functioning like this, the natural posture must necessarily be studied from a mental point of view, and from olden times the ultimate secrets of jujutsu have lain here.


Courtesy is the formal manifestation of the spirit of respect. With the spirit of respect we recognize the dignity of another's personality. In other words, it is the spirit of living in harmony with one another in social life. In a Judo contest the contestants should face each other in the proper posture, looking properly at each other and using moderation in their actions. Thus they are in a state of harmony in which they never set each other at defiance, and maintain the dignity of personality. Hence it is taught that exercises in Judo should begin with courtesy and end with courtesy.


In all athletic sports one must, in order to gain the victory, surpass the opponent in mental power, technical skill, and physical strength. These three factors must be united in gaining the mastery over an opponent. The mastery is brought into play in the form of various techniques, and although there are a large number of them, they may be summed up and resolved into one word sen (initiative or lead).

In the old densho (books of secret principles) the way of taking the initiative is explained in three stages.

  1. Sen-sen-no-sen (superior initiative). Superior initiative is given play in a delicate situation where one confronts an opponent who intends to attack, and gains mastery over him by subtly guessing his mentality and forestalling his actions. This is the highest reach of the mental cultivation in any military art and is regarded as not easily attainable. But if you consider it more deeply, you will find it too late to try to gain command over anything when it has taken a concrete form, and you must have the mental preparedness to hold it down beforehand. For this purpose it is necessary to learn to maintain the openness and serenity of mind as signified by the old expression, "Clear as a stainless mirror and calm as still water." Lao-tse teaches this almost divine state of mind in the following words: "It is the way of heaven to prevail without contention."
  2. Sen (initiative). This is to forestall your opponent by starting an action before he begins attack on you.
  3. Ato-no-sen (initiative in defense). This is not to guess the mentality of your opponent and check his action before it is done, but to start action in defense the moment you have an inkling of the offensive of your opponent. It is to avoid the opponent's attack the instant it is about to be launched upon you, and to make a counter-attack taking advantage of a pause in your opponent's movement and a disturbance in his posture. A man who takes the initiative in defense rises in opposition to his opponent's attack, and parries or averts it. Seemingly it is a defensive move. In order to stave off the opponent's attack at the last moment and restore one's position one must keep the moral attitude of initiative so as not to get worsted by the adversary.

The secrets of victory thus lie in taking the initiative, and in getting the start of one's adversary there are included the following factors:

  • The first is the eyes. From old times it is said that the important things in a bout are "first the eyes, second the feet, third grit, and fourth strength." The eyes are said to be the window for the mind. They are an index to your mind. Where the eyes are fixed, there the mind is concentrated, and naturally the will is attracted.
  • The second in importance is the posture. In a wider sense, it is the bodily attitude. It is a preparatory posture either for attack or for defense. Therefore, unless a proper posture is well maintained, not only is it impossible to take advantage of any opening for attack in the adversary, but you get your posture broken and are given a blow.
  • The third is the movement. Even though you maintain the proper posture or bodily attitude, you cannot attain your object unless your movement and action conform to the rules.
  • The fourth is the space condition. It consists of your distance, direction, and position as against your opponent. It is essential to study the principles of space condition, for from this study you will realize the secret principle of "fighting after getting the better of the opponent first."


Kenji Tomiki performing ude garamiKenji Tomiki performing ude garami

In the preceding section on the principle of natural posture, explanation was given regarding how to make oneself invulnerable to all possible attacks and how victory is gained. In this section on the principle of kuzushi (breaking the posture) it will he shown how it is that one is defeated. For in order to make clear the theory of victory one must at the same time know the theory of defeat. The Kodokan Judo found that the principle of the techniques (either with naked fists, or using a weapon like the sword, spear, club, etc.) of the old-school jujutsu consists in breaking the condition of the body which has lost equilibrium. It is called kuzure-no-jotai (state of broken balance). Sometimes the opponent himself loses the balance, and at other times you positively destroy the opponent's balance, leading him to a vulnerable posture. In Judo each technique is analyzed into tsukuri (preparatory action) and kake (attack). Preparatory action is further divided into aite-no-tsukuri (preparing of the opponent) and jibun-no-tsukuri (preparing of self). Preparing of the opponent consists in destroying the opponent's balance before performing a technique and putting him in a posture where it will be easy to apply it. At the same instant the contestant himself must be in a posture and position in which it is easy to apply a technique. This is the preparing of self.

The nicety of judo techniques lies not in the action of performing techniques, but rather in the skill with which the preparing is done as a preliminary. It was the clear-sighted and original idea of the founder of the Kodokan Judo that analyzed the technique which is applied in an instant, and attached importance to the study and practice of preparatory action. In the case of the preparing of the opponent, the theory and practice of the principle of breaking the balance must be studied, while as regards preparing of self it is necessary to study the natural posture and also the theory and practice of ma-ai (space condition).


The center of gravity of a standing man's body is nearly in the hypogastric region. When the perpendicular line drawn from the center of gravity passes through the fulcrum or the middle of the base formed by the two feet, the posture of the man is stabilized.

A man is ready to fall when his body swings forward and backward or from side to side, and the perpendicular line drawn from the center of gravity departs from the fulcrum. However, when a living person's body loses its balance, he tries to regain it. Though the center of gravity wavers, he is able to maintain his erect posture. In case the center of gravity of a standing person wavers sharply and he is unable to maintain stability he supports his body by putting his foot forward in the direction in which the center of gravity tends. In short, the posture of a standing man appears unstable at first sight, but the equilibrium is cleverly kept by taking steps properly. If some external force acts upon the man the moment he loses balance, he falls at once, as is described below

  1. The body falls easily, when something impedes the foot which is set in the direction in which the center of gravity tends, e. g., when the foot put out stumbles on a pebble.
  2. When the equilibrium of the body is lost, the time when the center of gravity is lost is shorter than the time required for the peripheral sensory organ to communicate the loss of the body equilibrium to the nerve center and the latter to order the foot muscles through the foot nerve to put the foot forward; for instance, when the body inclines forward and falls forward because a sudden force is applied from the back, giving the person no time to put the foot forward.


In the previous sections it was asserted that we are never defeated if we keep our proper posture and presence of mind, and in carrying on movements and actions we use the body in a natural and reasonable manner. It was also shown how easily we are defeated when the balance of the body is lost. Next we must learn how these two principles should be put into practice in the judo contest, namely how to deal with the opponent's power when applied upon us, and to gain the final victory. The rules of this activity are called ju-no-ri, or the principle of gentleness.

  1. The Principle of Gentleness as Viewed from the Relation of Force

    When meeting an opponent, there are various ways that the principle of gentleness can be applied against the force that is used upon us. The bout may be performed in a standing position or sometimes in a lying posture. There are also various kinds of techniques such as standing position techniques, lying posture techniques, holding techniques, strangle-hold techniques, and the bending and twisting of joints. In order to give the techniques full play in their respective situations it is necessary to apply the principle of gentleness.

    What then is the principle of gentleness? In the standing position techniques the contestant does not act against the force applied by the opponent, but, while following it, he makes use of the force and tries to break the opponent's posture. For instance, when you and your opponent confront each other at some interval, and he takes a step forward and pushes your chest with his hand, you too take a step backward instead of acting against him, and you will not feel the resistance of the opponent's force. If at that time your step backward is longer than the opponent's step forward, his balance is broken forward by his own force, and you can throw him down forward by pulling the arm which he thrust forward. If, again, the opponent pulls your front lapel, then you can throw him down in the same way by moving forward following the pull. In short, the principle is to pull in response to the opponent's push and to push in response to his pull. In other words, while yielding to the force of the opponent's action upon you, you break his balance by striking at the weak point in his posture. In this case it will be more effective to dodge the opponent's push and pull him by seizing that opportunity than to retreat in the direction of your opponent's push and pull him. The direction of the opponent's movement shifts around you and the opponent not only has to make more movement than you, but he is apt to lose his balance partly owing to the action of centrifugal force. The saying goes among judo experts, “ Move round in response to push." While following your opponent's action, you must always make your movement so as to lead your opponent around you and destroy the balance of his posture.

    This principle of gentleness means in a wide sense action to maintain your initiative against the resistance and obstruction arising from the surroundings. The manners of taking your posture, taking your steps and moving your body as taught according to the principle of natural posture indicates that the action against all resistance should follow the principle of gentleness. In regard to the case where your body loses its balance and you fall at last, breaking falls are devised as a means to protect your own body from the impact on the ground. This is also an application of the principle of gentleness. As was explained elsewhere in detail, when your own body is about to fall you should round yourself up and fall instead of resisting the impetus, while you use your arms to protect the body from the impact on the ground. In short, you avert the resistance of the ground while yielding cleverly to the terrestrial gravitation (which acts on you before you come under the opponent's force), and thus endeavor to exercise the initiative.

  2. The Principle of Gentleness as Viewed from the Relation of Movement

    In the foregoing passage explanation was given concerning the relations of the force between oneself and the opponent. It must further be given from the relation of movement. In a bout your opponent develops a feverish bodily activity; so it does not turn out as you want it to. For instance, it would be difficult for you to deliver a blow on your opponent's face, forearm, or side, or to sweep his foot or waist, because the opponent does not stand still a moment, either. Still more difficult is it to grasp the opponent's wrist or arm. An old book of secrets in martial arts mentions the three following opportunities to land a blow on the opponent:

    • Giving a blow at the beginning.
    • Giving a blow at the finish.
    • Giving a blow on the receipt.

    "Giving a blow at the beginning" is effected when the opponent is beginning an action in which he shifts from a stationary state. Close observation reveals that a man's movement is a succession of rest and motion, resting followed by motion and motion by rest. You land a blow on the opponent at the turn of his action. For instance, when the opponent strikes with his fist, he must first raise it. The moment he begins to raise his fist and the moment he begins to deal a blow with his raised fist are called the "beginning." In "giving a blow at the finish," "finish" means the moment the opponent has dealt a blow with raised fist and forearm fully stretched. "Giving a blow on the receipt" is effected when the opponent has received the blow you gave him and, intent only on parrying it, has ceased all other action.

    In all these cases you avail yourself of the pause at the change of one action to another. By taking advantage of the three above-mentioned cases you give a blow, grasp, or parry. But as a matter of fact, you must be more careful. The pause at the turn of one action to another means the instant the opponent comes to rest. The instant may perhaps be a minute fraction of a second and so it is difficult to give a blow or a grasp just that instant. When, for instance, you chase a fly or dragonfly, you often fail if you try to catch it the moment it settles on something. You will succeed if you catch it by adjusting the motion of your hand to the speed and direction of the insect before it alights. Thus one realizes that in order to seize the three opportunities giving a blow successfully, it is necessary to have practice in adjusting the rhythm of your action to that of the opponent's motion. One cannot understand the principle of gentleness unless one learns this relation of rhythm. As with the way of movement in the natural posture, it is possible to adjust the rhythm of the motion of your body to that of the motion of the opponent's body. It is only when the rhythm of the body movement is thus in accord that you can make the rhythm of your foot and hand movements in accord with that of your opponent and seize the opportunity of applying various techniques.

    The application of the principle of gentleness is well manifested in the techniques and five kata (forms) of the (ito school of jujutsu which are preserved as the koshiki-no-kata (forms antique) of the Kodokan Judo. The application of force and the movement of the body are effected quite naturally without causing any strain, and enable the contestant to bring the opponent under control without acting against his force. The movement makes a magnificent and beautiful rhythm. From olden times the principle of gentleness has been symbolized by a willow branch or a bamboo, which is pliant and not easily broken. It was also likened to the movement of billows rolling in and receding on the beach. Many of the old schools of jujutsu took their names from these symbols. The term aiki as used in the aikijujutsu or aikido signifies after all "gentleness." The Orientals sought the source of all human actions in ki (spirit). Force is derived from spirit, and movement of the body is effected by spirit. So they held it of primary importance to foster spirit. Mencius says: "Will leads spirit; spirit permeates the body." Issai-Chozan, ancient swordsman, writes, "Spirit carries the mind and controls the body." To adjust one's own spirit to the opponent's is to adjust one's own power to the opponent's, and this is an internal explanation of the principle of gentleness.

    Kenji TomikiKenji Tomiki, author of "Judo, with Aikido", published in 1956

    Jujutsu (art of gentleness) was also formerly called wa-jutsu (art of accord). This shows that ju (gentleness) has also the meaning of wa (accord). In the Ryuko-no-maki (lit. Book of Dragon and Tiger) which is regarded as one of the oldest volumes expounding the secrets of the martial arts, there is a passage, "If the enemy turns upon us we meet him; if he leaves we let him leave. Facing the enemy, we stand in accord with him. Five and five are ten. Two and eight are ten. One and nine are ten. All this shows accord."

    Wa, or accord, is the fundamental principle of the Japanese martial arts. Expressed in modern terms and made easy of practice to anyone, it became the principle of gentleness. The principle of gentleness teaches that one should go, not against, but with, the the opponent's force, and yet maintain one's proper position so as not lose one's balance. This corresponds to the spirit set forth in Confucius' remark in his Analects, "The superior man is compliant but not blindly yielding." Jujutsu originated as a method of fighting between men. But through practice by experts for many years it has been refined as an art, with its principles more and more closely studied and invested with moral significance, until it has developed into Judo as we learn and practice it today. Judo is neither a mere manifestation of violence nor a means of fighting, but can be studied and followed as a doctrine of life.


     Taken from the Judo Information Site - with kind permission from  Neil Ohlenkamp