Dharma may be defined as the highest good. Its idea is not limited to sense perception, and requires a proper teacher to explain it. It arises from action, which is the law of life. Success arises from action; and action cannot be renounced. There is action even when we do not see it, which is both eternal and universal. However, there is a difference between natural and deliberate action; and the subject matter of the Vedas is action.
The idea of dharma does not arise from sense-perception, because the latter is limited to what is present, while the idea of dharma goes beyond the present. As it is conceived to be the highest good. Which is a valid means of acquiring knowledge, and does not require the authority of a Badarayana to prove it. (Badarayana is the name of the celebrated author of the Vedanta Sutras).