The concept of hard/soft and external/internal martial arts is not one easily described. In terms of styles which most people are familiar with, Karate would be an example of a hard style and Aikido or T'ai Chi examples of soft styles. A hard style is generally considered one where force is used against force; a block is used to deflect an incoming strike by meeting either head on, or at a 90 degree angle. A soft style does not use force against force, but rather deflects the incoming blow away from its target. There are uses for both hard and soft techniques. A practitioner may wish to break the attacker's striking arm with the block. On the other hand, a much smaller opponent would not be able to accomplish this, so instead may wish to deflect the incoming attack.

An external style is one which relies primarily in strength and physical abilities to defeat an opponent. In contrast, an internal style is one that depends upon ch'i and timing rather than power. Aikido (at the master's level) would be an internal style, while most karate styles are external.

However, the concepts of hard/soft internal/external are finding fewer proponents among senior martial artists. Both conceptual twins are impossible to separate in reality, and masters will generally acknowledge that any distinction is largely only a matter of subjective interpretation. Arguments about the reality of the concepts are often waged by novices and philosophical dilettantes, ignorant of the inseparable nature of duality. They see yin and yang as elements that can exist independently, while philosophical and physical reasoning demonstrate that they cannot. Without their union (=Tao), neither can exist. Ergo, a "hard" technique such as a straight fist is guided by the soft power of mind and the internal component of ch'i. Equally, the softest projection of Aikido requires the "hard" element of physical contact and movement, coupled with actively redirecting the opponent. In short, preoccupation with distinguishing soft from hard is a distraction from learning martial arts and moving towards a unifying technique and mastery.