Yatharthajnana is a term in Hindu logic meaning ‘actual cognition’. It is also known as prama in Hinduism. This compound word yatharthajnana consists of three words – yatha ‘as’; artha ‘meaning’ as object of knowledge; and jnana ‘perception’. Yathartha means artham anatikramya (‘undeviated from the meaning’). The word jnana is formed out of the root jna – ‘to know’. ‘Actual cognition’ only happens when such a perception of an object does not differ from the original. For example, suppose a man sees a silver coin from a distance and cognizes that object as a silver coin, then that cognition is ‘actual cognition’; if another sees an oyster’s shell from quite a distance and cognizes that shell as silver, then that cognition is false and is called a fallacy. The technical derivation for yatharthajnana is tadvati tatprakarakam jnanam (the cognition of something in the right manner). Its opposite is ayatharthajnana or aprama defined as tadabhavavati tatprakarakam jnanam (the cognition of something as false).
According to Vedantins, the term ‘actual existence’ is only used for Brahman. If a person cognizes all substances in the universe, from the smallest to the biggest, as the Supreme Self, then his cognition is an ‘actual cognition’.
Actual cognition (or yatharthajnana) is realized by a person only when obstacles such as ignorance are removed. But in the case of a yogin, one who has attained yogic power through spiritual perfection, it is a constant perception. A Yogin does not perceive anything apart from the ‘actual cognition’. Through this ‘actual cognition’, everything is revealed to him. A yogin himself is an ‘actual cogniser’ or a yatharthajnanin. He cognizes the whole universe exactly as the universe is. This perception is yatharthajnana.