(Sanskrit: "rule, method")

Philosophical subdivision within hinduism, one of the six classical orthodox systems (darshana) of Indian philosophy.

The basic text of nyaya philosophy is the Nyayasutra, which is usually ascribed to Gautama (active c. 100), also called Akshapada. The transmitted form of the Nyayasutra probably dates back to the 2nd or 3rd century.

Nyaya sets up a cognitive system with 16 categories of logic. It shares many characteristics with another of the six orthodox philosophies, vaisheshika; over time, the two systems melded to form a single tradition.