Nyaaya system by Rishi Gauthama is the science of debate and discussion with reasoning and arguing. Logic is only a part of the Nyaya. It tells that knowledge implies four conditions: (i) the subject or Pramaata, (ii) the object or Prameya, (iii) the resulting state of cognition or Pramiti and (iv) the means of knowledge or Pramaana. Nyaaya says that the actions of man produce their fruits called adrishta which is supervised and controlled by God. God does not alter the course of adhrishta but renders its operation possible as the bestower of fruits of action. The cause of bondage is ignorance (Ajnaana). Twenty-one kinds of pain constitute bondage. Isvara has Eternal knowledge or nithya-jnana, who also has desire- action (Icchaa-Kriya) as qualities or gunas. He is all-pervading or Vibhu. False knowledge or mithya-jnana is the root of all misery and pain. It leads to the faults of likes and dislikes and proceeds to karma or action, good or bad. This forces a man into repeated cycle of birth as reward or punishment. Moksha is the destruction of pain and bondage. One gets the release and attains supreme felicity by realizing true knowledge of the Aathman.

Vaiseshika system by Rishi Kanada arranges its inquiries into categories (padarthas); such as substance, quality, action, general and particular property and non-existance. The knowledge of padartha is the means of attaining supreme good, resulting from the knowledge by a particular dharma. Sage Kanada does not openly refer to God in his suthras. The formation of the world was the result of adhrishta, the unseen force of karma or actions. The followers of Kanada introduced the concept of God as the efficient cause of the world. The atoms are the material cause of this universe. The body is subtle in pralaya and gross in creation. The time, place and circumstances of birth, family and life span are all determined by adhrishta. Conjunction of soul with body is called birth, disjunction is death and moksha is the non-existance of the conjunction with body, no potential body existing. Pleasure and pain result from the contact of soul, sense, mind and object. Desire and infatuation or moha arises from pleasure and aversion or hatred arises from pain. Intuitive knowledge of the Self destroys false knowledge. Consequently, all faults of moha will vanish.