There is a controversy in the world of aikido concerning the heritage of Morihei Ueshiba.
Some tell us that he had a deeply religious and spiritual vision that was entirely unique and Japanese. This vision, as such, couldn’t pretend to become universal. The Japanese themselves admit that they had difficulty grasping the Founder’s way of thinking. If Kishomaru Ueshiba, his son, had not formalized aikido by structuring the practice—separating, along the way, everything related to this line of thought—it is likely that aikido would not have experienced the development that it is seeing today. Ueshiba’s heirs, those students who had the privilege of following his teaching, carried on his memory, or at least what they grasped and made an impression on them. While practicing, each of them was seeking answers to personal questions, so it is normal that they all found different answers. When observing as a whole the schools or styles of aikido that followed in the footsteps of the Founder’s direct students we find the elements of the philosophy that Morihei Ueshiba wanted to pass on because the spirit of aikido is inseparable from its practice. Chase it out the door and it comes back in through the window.
Those who focus mainly on the technical practice of aikido are often ill at ease when facing the challenge of joining the spirit to the movement. They prefer to argue that there is no aikido without the perfect mastery of movement and that it is itself an endless path. Just because the path of technical progress is long does not mean that it has no end. We are limited by our physical ability, which evolves following a bell curve: we progress in technical mastery and physical condition until a peak, around the age of thirty or forty, then our abilities naturally decrease over the years. We can adapt our aikido practice to our physical condition and thus be able to practice for a long time.
Although we can be delighted about this, we cannot hope to reach our golden years without experiencing its effects. The myth of eternal youth still has a bright future ahead of it, especially when it is perpetuated by the advocates of our consumer society. One can consequently wonder if this sort of aikidoist isn’t on a quest for some Holy Grail of perfect movement and nothing else. Most will stop along the way because of weariness or after the accumulation of small injuries and sprains or the consequences of thousands of falls they have taken during their long career on the mats.
It is surprising that we can talk so much about the virtues of peace, harmony, and nonviolence in aikido. However, these qualities appear very little in our behavior. Obviously, the very act of practicing does not inevitably bring the virtues of peace and harmony that everyone sees in aikido. As a result, there is a strong temptation to take refuge in a form of practice that has lost its martial qualities and retains only the spirit. There again the result will not materialize.
By cutting off aikido from its physical dimension, you take away what makes it special, that is, the embodiment of a philosophy. The answer is to be found in the joining of the two aspects that make up the essence of aikido: movement and meaning, body and mind. I often illustrate this with the metaphor of two-part adhesive that is used, for example, to repair kayaks. These glues are made of two tubes containing products which, taken separately, cannot glue anything at all. However, once they are combined and applied together they have exceptional adhesive characteristics. It is the same for aikido: movement without meaning is simply gymnastics, meaning without movement is just useless talk .
While the physical dimension has been the subject of a precise formalization and worldwide consensus, we must wonder about the meaning of aikido practice. What do we mean when we talk about the meaning of aikido?
The primacy of physical practice has often reduced the spirit of aikido to a few slogans that are repeated in dojo advertisements. To avoid clichés and fancy words, it is necessary to look at the message that Morihei Ueshiba wanted to give to us and to separate what belongs to the esoteric Buddhism that moved Ueshiba, from the universal aspects that could touch every human being.
 Aside from two or three older students who are no longer with us, the direct students of Ueshiba were young Japanese, around twenty years old, who had difficulty understanding his speech and focused on the practice of techniques (according to the eyewitness account of Seishiro Endo, current technical director of the Tokyo Aikikai, during seminars that he has led in Belgium.)
 Traditionally, a master’s students (deshi) who lived in his house (uchi) were known as uchi-deshi.
 The quarrels between schools come more from questions of style and variations than from disagreements on the fundamentals.