Ki - Way of internal strength/power
Do - Way - Achieve
Hapkido is the uniting of energy when force is blended/united with force, i.e. using power of aggressor with your power - and controlling the situation. This can be achieved not only on a physical plane but also on a mental plane.
Philosophy of Hapkido
To be Rightous - Rightousness
To be Courteous - Courtesy
To be Patient - Patience
