Direct perception, inference, and valid testimony are the sources of correct knowledge.

The three sources of pramāṇa (valid knowledge):

1. Pratyakṣa — Direct perception through the senses. It is the immediate contact with the object.

2. Anumāna — Logical inference. We deduce what we do not directly perceive from what we do perceive (seeing smoke and inferring fire).

3. Āgama — Authoritative testimony, scriptures, or the word of those who have realized the truth. Also called śabda.

These three sources are accepted by most Indian philosophical schools. Yoga recognizes that, although these sources provide valid knowledge, they remain mental modifications that must eventually be transcended.