-What is the difference between "fundamental techniques" and "basic techniques"?
-The fundamental techniques are primary. If we draw a parallel with mathematics, the fundamental techniques would be akin to the Five Principles of Euclid. Those fundamental principles are the basis of applied geometry. Since the fundamental techniques are like maxims, there are no movements in Aikido that violate those principles. Basic techniques are those techniques deduced from the fundamental techniques, during training the proof of the maxims is clearly demonstrated.
There are those who like to make up their own maxims, but this is not possible in Budo. All the movements have to follow natural principles, and cannot be artificially constructed.
Here is an example:If you drop a stone it will fall to earth because of gravity, and that principle can never be challenged. It is a maxim that must be observed, and once that is understood as a base it can be utilized. From that fundamental maxim, the basic movements emerge, and from the basic movements variations spring forth.
Kisshomaru Ueshiba Doshu
Nel video, un giovanissimo Endo Seishiro come uke.