As described in the Patanjali yoga system, pramana-viparyaya-vikalpa-nidra-smrtyah. By intelligence only one can understand things as they are. By intelligence only can one understand whether or not he is the body. The study to determine whether ones identity is spiritual or material begins in doubt. When one is able to analyze his actual position, the false identification with the body is detected. This is viparyasa. When false identification is detected, then real identification can be understood. Real understanding is described here as niscayah, or proved experimental knowledge. This experimental knowledge can be achieved when one has understood the false knowledge. By experimental or proved knowledge, one can understand that he is not the body but spirit soul.

Smrti means memory, and svapa means sleep. Sleep is also necessary to keep the intelligence in working order. If there is no sleep, the brain cannot work nicely. In Bhagavad-gita it is especially mentioned that persons who regulate eating, sleeping and other necessities of the body in the proper proportion become very successful in the yoga process. These are some of the aspects of the analytical study of intelligence as described in both the Patanjali yoga system and the Sankhya philosophy system of Kapiladeva in Srimad-Bhagavatam.