Ancient India

The Indian philosophies of that time - the Nyaya and the Samkhya - did not hold the passive view of the learner apparently espoused by Plato. The Nyaya (Gautama, 4th or 5th C. BC) accepted that information obtained through the sense organs is reliable. In that sense these were empiricist theories, in contrast to Plato's rationalism which was dominant in Greece. The Nyaya assumes we exist as embodied beings, receiving information through the sense organs and acting on the world about us through the organs of action, filtering information to consciousness through the mind, manas (which is also the location of the emotions), and processing it in the intellect, buddhi. According to Nyaya memory consists of traces of past experience on the mind and it plays a role in perception. This is a constructivist view, clearly distinct from Ancient Greek thought.

Nyaya and Samkhya thought of the mind as the controller and believed in the active construction of knowledge through:

• Perception (the data of the senses brought into order by mind). Incidentally included a belief in eye-rays.

• Inference (based on existing knowledge from perception, comparison or testimony). Inference moves from the known to the unknown via causal - not logical - reasoning. Nyaya sees inference as of three kinds, cause-to-effect, effect-to-cause, and what-is-commonly-seen.
  • cause-to-effect: I see black clouds approaching and infer it is going to rain.

  • effect-to-cause: I see smoke pouring from the window of my house and infer something is burning.

  • what-is-commonly-seen: I see a tall, powerfully built person with a long, full beard and infer the person is male.

• Comparison (defined similarly to inference: comparison may be based on categories rather than causal relations but distinction from what-is-commonly-seen is not clear.)

• Verbal testimony (shabda, the testimony of a relevantly expert person)

Ref: http://www.philo.demon.co.uk/doctrine.htm