There is no letter which is not a mantra(which cant be used in mantra), there is no root, which can't form some medicine, there is no person who is absolutely useless. But persons who can identify their utility and put them in proper usage are rare.
The word "dharma" is derived from verb "dharaNa". it is "dharma" which holds society together. Hence if something is able to hold people together, no doubt it is dharma.
Eating (or things needed for survival), sleep, fear from somebody and sex life (for reproduction), these habits are common between human beings and animals. It is "dharma" which is additional important quality of man, without which he is same as an animal.