Take unbendable arm, the test is first with strength and then with ki and extension. Take a strong posture and have this tested by means of lifting or being pushed and compare with the same posture with ki, relaxation and weight underside. These exercises have been tried by all of us and you continue to learn by studying them. These basic tests prove in fact strength is weaker than by using the four elements we teach and study in Aikido:-
1) Concentration on the one point.
2) Weight underside.
4) Extension of ki.
These are the four principles of ki, lose any one of these elements and you lose the other three.
The tests mentioned above show simply that Aikido in the early stages is full of paradoxes.
There are ways that are seemingly natural that aren't: that must be relearnt with different emphasis. Whilst Aikido is a defensive art a beginner will no doubt consider success in a technique as being the ability to put down an opponent. Unfortunately if this attitude prevails in any more than the short term, progress in Aikido will be slow.
Examine the way Aikido is practised: -
a) Gou-No-Keiko To practice hard and full strength mostly by basic technique.
b) Jyu-No-Keiki To practice softly with the principle of non-resistance, but still practicing attack and defence.
c) Ryu-No-Keiko To practice very softly as running water and there will be no attack and defence. Nothing will be opposed between opponents and partners by perfect harmony and peace. This style of practice is only possible for high Dan grades.
This I consider shows the way our Aikido should develop, but if you remain at learning basic (Gou-No-Keiko ) the harmony, leading and controlling an attacker will not develop, as it should. Therefore once you have proved to yourself that Aikido works at a basic level you should study the next level. The attacker and defender should study and develop a soft flow. It is from this level that techniques become more powerful and effective even though less strength/effort is employed. This is a paradox reached by pupils once they reach a physical understanding of the techniques.
Andrew Baird. Published 1984