Soft Vs Hard
Soft is yin, hard is yang. Contraction is yin, expansion is yang. Aggressive thinking of the west has us believe yang is better than yin. The world normally acts on the yang, pays attention to the yang, and forgets the importance of the balance of yin. Do not let modern thinking get in the way of following the way of the Dao. Following the way is to learn how to balance and harmonize the yin/yang in ourselves and in the world.
Many Tai Ji Quan and Qi Gong practitioners suppose the opposite; yin is better than yang. However, too much of either one is unhealthy. The softness of the yin will allow the strength of yang to grow, which will lead to the inability to move. This also is a mistake.
The hardness of yang weakening into yin will lead to a deflection of an attack. If done correctly (which takes years upon years of training), the balance in your body will always be there and you will be undefeatable. The attributes of the yin/yang are always there, we just need to find them.
There is a concept of iron (yang) and silk (yin) in martial arts and Tai Ji Quan. It is learning how to exploit both kinds of basic energy to the practitioner's advantage.

These two are held up with silk. Silk is soft, but can be very strong.