Buddhist philosophy, based on the teachings of Gautama Buddha, has these main tenets: Life is characterized by suffering (sarvam duhkham); every being in the world is momentary, changing and unstable (sarvam kshanikam); everything is caused by something else; nothing has an absolute existence of its own (samudaya satyam and karana satyam); and there is a way out of suffering (marga satyam). These are the four noble truths.

        Buddhism believes in the ‘law of Karma’ operating in this life and in the next. Every effect is caused, and every cause has an effect. The Buddha discovered the twelve-linked claim of causation (of cause and effect) which is Ignorance (Avida), Impressions of past actions (Samskaras), Consciousness (Vijnana), Psychophysical Organism (Nama-rupa), Sense organs and the mind (Sadayatana), Contact of the Sense-organs with objects, (Sparsa), Sensations (Vedana), Thirst for Sense-enjoyments. (Trsna), Clinging to the enjoyments (Upadana), Will to be born (Bhava), Birth or Rebirth (Jati) and old age and Death (Jara-marana).

        To get out of this chain of causation one must aim at Nirvana (cessation of birth and death and of suffering consequent upon them). Nothing more can be said of Nirvana than that there is complete cessation of suffering in it and of all that is regarded as evil in life.

To enter Nirvana, one has to give up Trsna completely, and to follow the Eightfold Noble path (the Astangi Arya Marga): Right Faith (Samyak Drsti), Right Resolve (Samyak Sankalpa), Right Speech (Samyak Vak), Right Action (Samyak Karmanta), Right Living (Samyak Ajiva), Right Effort (Samyak Vyayama), Right Though (SamyakSmrth) and Right Concentration (Samyak-Samadhi).

In some place the Buddha is said to have summarized the whole process in a triple formula, namely, Sila (Right Conduct), Samadhi (Right Concentration) and Prajna (Right Knowledge). The first two lead to the last which is the direct cause of Nirvana or Liberation. The Buddha advocated “The Middle Path” in which the extremes are avoided.

        After the death of the Buddha his teachings were collected, revised and interpreted differently. Several schools of Buddhist thought come into distance, four of which are well-known: the Vaibhasika, the Sautrantika, the Vijana – Vada and the Madhyamika (Sunya-Vada). The last two schools have played a great role in the later development of Indian the renowned leader of Vijnana-Vada and Nagarjuna that of the Sunya-Vada.)

        The Vaisesika system is a realistic, analytic, and objective philosophy of the world. It tries to distinguish various kinds of ultimate things from one another and to classify all the objects under distinguishable categories. All the objects of knowledge, according to this system, fall under six categories (Padarthas) namely, substance, (Dravya), attribute (Guna), action (Karma), genus, (Nati), differentia (Visesa) and inherence (Samavaya). There are nine different – Earth, Water, Air, Fire, and Ether-existing in the form of Atoms, Time, Space, Minds and Selves. The world is a complex and composite formation of these substance, which comes into being and is destroyed at times.

        The Niyaya system accepts all the categories recognized by the Vaisesika system and adds a one Abhava (negation). It also accepts all the substances admitted by the Vaisesika system and considers God to be the creator (designer) of the world as the efficient cause. He is a soul (Atman) free from the ‘Law of Karman’ and rebirth. His wisdom, desire, and effort are unbounded. He is the author of the Vedas. He cannot create or destroy any of the substances which exist eternally.

The ‘Law of Karman’ operates independently of Hi. He creates the complex, objects of the world out of the pre=existing atom. The soul is co=eternal with God and is infinitely extensive in dimension. (Vibhu), but in itself it is not conscious. Consciousness is a quality which arises or emerges in the soul when the latter comes in contact with the mind, senses and the body.

        Nyaya makes a detailed study of the sources of Knowledge (Pramana) which it recognizes to be four, namely, Perception (Pratyksa), Inference (Anumana), Comparison (Upamana) and Verbal Testimony (Sanda). The study of the Pramanas and Hetvabhasa (fallacies) are the special features of this school. That is why it is called Nyaya (Logic).