O'Sensei speaks of it in his writings and poems;
"It is essential that WAZA (practice / training) always be in accord with
the truth of the Universe. For that to take place proper NEN (thought) is necessary. If one's NEN is connected to the desires of the small self, it
is erroneous. Since training based upon erroneous ideas goes against
the truth of the Universe, it invites its own tragic consequences
and eventual destruction."
To train for oneself is negative and will prevent the mind, body unification which WAZA perfects. Aikido is not just another method of self defense but a method of self-realization and self-perfection for the perfection of the world and the Universe.
Tohei Shihan and Kashiwaya Sensei speak of positive KI as well. At a seminar with Kashiwaya Sensei, I remember him writing on the whiteboard about positive projection and how this positive thought makes the brain work harder. Just as how exercise promotes a healthy physical body, mental exercise promotes a healthy spirit and assists in the unification. Daily training provides both.
When I first began training, there were many classes where Sensei Medeiros would lecture while we sat in SEIZA (kneeling position). That was the whole class to Sensei, trying to keep the blood flowing to your legs and feet, listening and working out the verbal teaching in your mind. I remember going home exhausted and wondering why...we didn't do techniques. There were also many classes where we physically trained very hard and I would go home invigorated and not wake up sore the next morning. So Aikido training is many different things at many different times but the training must always focus on positive KI. Knowing that there is negative energy being created in the world such as war, poverty and illness should not allow your own thoughts to dwell on them but recognize that the world is not perfect. But to also know that if you project strong positive KI, it may help others to project the same and a utopian society is truly possible.
We all came to Aikido for different reasons and when we first stepped on the mat we humbled ourselves to what the art was about to present. As Maida Sensei said; "It's simple...not easy but simple." We train in Aikido with many, many things to think about both during training and afterwards and it can make us frustrated at times, it can make us angry but make us happy as well. Every time negative thoughts such as anger and frustration fill your body, STOP and in that moment, think about why you allowed those feelings to manifest. Then relax, breath in deep to your HARA (belly / anatomical center), hold in the positive air letting it nurture positive KI and exhale the negative manifestations you created. Do this daily at work, home and during training. There is no need to create negativity since there is already so much out there. Help to promote the truth of the universal and the benefits are infinite.