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Dignaga

Buddhist · South Asia · 480 to 540

Indian Buddhist logician who held that there are only two sources of knowledge, perception and inference.

What it is

Dignaga was an Indian Buddhist philosopher and logician who lived around the fifth and sixth centuries of the common era. The sources give slightly different dates, and little is known of his life. He is remembered as one of the founders of Buddhist logic and for arguing that there are only two sources of knowledge, perception and inference.

His main work is the Pramanasamuccaya, a title often translated as a compendium of the means of true knowledge. In it he deals with perception and with inference, the two ways of knowing he accepted, and with what makes a piece of evidence good. Later Buddhist thinkers, such as Dharmakirti, took his tradition further.

The main ideas

  • Two means of knowledge. Perception and inference are the only two instruments of knowledge.
  • Two kinds of object. The reason there are two is that there are two kinds of thing to be known: particulars and universals. A particular is the single thing met directly, such as a patch of green. A universal is a general feature, a class or a name shared by many things.
  • Perception without concepts. He defined perception as knowledge free from all conceptual construction, including names and class concepts. In effect, only pure sensation counts. What we call seeing an apple, with its name and its category, already adds thought to the raw data.
  • Inference deals in concepts. Inference works with general features. When we see smoke and conclude that there is fire somewhere, what we know is a concept, the presence of fire, and not a fire standing before us.
  • Inference for oneself and for others. He separated reasoning that one does for oneself from the argument one sets out for another person.
  • What makes a sign good. A sign, such as smoke, is good evidence only if it meets three conditions. One of them is that the sign must not be found in cases that lack the property in question, so that smoke can point to fire only because smoke does not occur where fire is absent.
  • A study of reasons. He also wrote the Hetucakra, the wheel of reasons, a work on logic that deals with reasons given for a conclusion.

What it looks like in practice

Imagine someone on a hillside who sees smoke rising from a distant ridge and says there must be a fire there. Dignaga would separate two moments. What the eye receives, a grey column, is perception. The step to fire is inference, and it holds only because smoke is found where fire is and not where fire is absent. He would add that the thought of fire cannot warm anyone, while a fire close by can. This is an illustration of his line of thought, not a passage from his writing.

Books and moments

  • Pramanasamuccaya, his major work, laid the foundations of Buddhist logic.
  • Hetucakra, the wheel of reasons, is a work of his on formal logic.
  • Dharmakirti developed Dignaga's tradition in the seventh century.

Questions and criticism

  • Seeing without concepts. It is fair to ask whether anything can be perceived without any concept at all, since ordinary seeing seems to come with names and categories.
  • Only two. It is fair to ask whether testimony, comparison or other ways of finding out really reduce to perception and inference.
  • A thin record. Because little is known of his life and the dates are uncertain, it is fair to ask how much of his own thought can be told apart from the tradition that followed him.

Close neighbours

The page on Dharmakirti is the closest, since he carried Dignaga's tradition forward. The pages on Vasubandhu and Nagarjuna show other Buddhist philosophers of India.

Written by epchē in our own words, and checked against independent sources on 29 October 2026. The sources are listed below.

Who they connect to

Influenced

  • Dharmakirti · Dharmakirti commented on his work and carried his system forward.

Influenced by

  • Vasubandhu · Tradition names him as a student of Vasubandhu, and his logic builds on mind-only ideas. (scholars disagree about this link)

Other Buddhist thinkers

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