In the comprehension of the truth about the Divine, there are four different approaches. These are: Yastika, Astika, Astika-Nastika and Nastika. Yastika is one, who, on experiencing a Divine fragrance, seeks to find out the source of the fragrance and after a diligent search, gets at the flower, which is the source. In spiritual terms, this means that the seeker studies the Vedas, the Puranas and other Scriptures and tries to realise the Divine as revealed by them. Yastikatva means embarking on a diligent search to discover the source of the Real and to experience it.

Astikatva is devoting one’s entire life to the search for the source of the fragrance.

Astika-Nastikatva means, making the search for the source of the fragrance and, on failing in attempts, giving up the search out of frustration and despair.

Nastika is one who denies the existence of the fragrance, because he is afflicted by a disease, which prevents him from smelling the fragrance.(SSS Vol.24, pp. 20-21)