The Yin & Yang-Theory (Vietnamese: "Âm-Dương") states that everything in the universe and on earth is initiated through the interrelation of Yin (negative) and Yang (positive). As to this theory there are martial arts that prefer the hard over the soft and others that prefer the soft over the hard. Vovinam Việt Võ Đạo does not prefer any over the other. Hard and Soft are used equally to adapt to every situation, to every problem.
Based on Võ-Thuật the student aims to develop the ability to combine hard and soft at the right relation, in combat and in daily life. This aiming to develop both physical abilities as well as the student's spirit. Not only the principle of the harmony of hard and soft but also many other things resulting from the training contribute to internalizing the martial art philosophy, e.g. fighting spirit, courage, tenacity, fairness, modesty and tolerance. Above all the training morality and the way of applying the techniques shape the students' character.
The greatest difficulty is to see through ones own ego and then to overcome it.
On success in doing so the Vovinam student will gain generosity and tolerance with other people.
With the awareness that the most important thing in life of a human are other humans the final goal is to be able to not only help oneself but also to help others to live in peace and harmony with ones surrounding.
With the salutation, "Iron Hand over benevolent heart" the student is reminded about the main principle and about the goal of Vovinam Việt Võ Đạo with every training. It is also about using the opponent's force and reaction, hence reach maximum effect with little force/effort.