First is the maxim which says that one should pay close attention to the relationship between self and other. To take an example, before making an attack, one should note his opponent’s weight, build, strong points, temperament and so on. He should be nonetheless aware of his own strengths and weaknesses, and his eye should critically assess his surroundings. In the days when matches were held outdoors, he would inspect the area for such things as rocks, ditches, walls and the like. In the dojo, he takes note of walls, people or other potential obstructions. If a person has carefully observed everything, then the correct means of defeating an opponent will naturally become apparent.
The second point has to do with taking the lead. Players of board games like chess and go are familiar with the strategy of making a move that will entice the other player to move in a certain way. This concept is clearly applicable to both judo and our daily lives.
Stated succinctly, the third point is: Consider fully, act decisively. The first phrase is closely related to the first point above, that is, a man should meticulously evaluate his adversary before executing a technique. This done, the advice given in the second phrase is followed automatically. To act decisively means to do so without hesitation and without second thoughts.
Having shown how to proceed, I would now like to advise you when to stop. This can be stated quite simply. When a predetermined point has been reached, it is time to cease applying the technique, or whatever.
The fifth and final point evokes the very essence of judo. It is contained in the saying: Walk a single path, becoming neither cocky with victory nor broken with defeat, without forgetting caution when all is quiet or becoming frightened when danger threatens. Implicit here is the admonition that if we let ourselves be carried away by success, defeat will inevitably follow victory. It also means that one should always be prepared for a contest–even the moment after scoring a victory. Whether a person’s surroundings are calm or turbulent, he should always exploit whatever means are at hand to accomplish his purpose.
– Jigoro Kano, Kodokan Judo