The warrior's heart
"The warrior's heart is ruled by preparedness, and Nature's heart, or God's heart, is fundamental. The heart also governs the warrior's physical kamae. Therefore, if there is no unity in spirit and body, you will never understand the reason for being a martial artist.
You will leave no vulnerability or opening (suki) if you remain consistently prepared. When the opponent assumes a kamae to try and cut, they will be unable to touch you. To show the determination 気迫 (kihaku) that you will immediately knock over an opponent with your fighting spirit 気合 (kiai) - this is the form of calm courage and the quiet heart of a divine posture.
The enemy's attack is held back by your determination an they are temporarily paralyzed 不動金縛りの術 (fudo kanashibari no jutsu) as they are knocked down from a distance by your thundering cry 遠当ての術 (tōate-no-jutsu - the art of striking from a distance). You should know that unless you have this determination in your practice, then the gokui of 'muto dori' cannot be obtained."
DR. MASAAKI HATSUMI