Anusthana in Hindu religion is the performance of various rituals with dedication as ordained by source texts like the Vedas and Tantra. Anusthanas are important because dharma or righteousness is ensured not by merely knowing how to perform the various rituals but by performing them. There are rituals which are obligatory and rituals which are optional (nitya and naimittika karmas).
One who performs the various rituals is known as dharmika.
Shruti, smriti and sadachara (right conduct) are the three means of dharma, as
accepted by those who interpret Vedas. Thus, sadachara has an important place
in the life of Hindus. As long as a person has body-consciousness and cognizes the
difference between the doer, the act and the result, he has to perform the various
rites without fail. Even after attaining knowledge of the Absolute, he may
continue to perform these rites. He will not, however, be affected by them,
because he performs them only for the sake of the welfare of the society.
Even though the modus operandi is laid down clearly in the knowledge
texts, it may be difficult in practice to follow all the rules, prohibitions,
exception, etc. If there is any doubt about the method or the time of
performing the various rituals because of the ignorance of the necessary
textual knowledge about them, then it is enough if they are done by following
the practice of an eminent person.
All the knowledge of the knowledge texts is not equal to
even an ounce of actual practice. Thus, actual performance, called sadacara or
anusthana, is important in the scheme of Vedic life of Hindus. According to Veda
Vyasa, ‘Dharma is the result of achara and Bhagavan is the controller of
dharma.’