The agent and the instrument of an action must be distinguished from one another, just as the axe-man (agent) is distinct from the axe (instrument) in the act of chopping

This is a convenient place at which to introduce the last of the nine substances, the ‘mind’ (manas). It is defined by The Manual of Reason (TS18) as a sixth sense-faculty, one by which a person ‘perceives’ their inner mental objects (beliefs, pleasure sensations etc.) In other words, it is a faculty of introspection. Naturally, we need an argument why this faculty cannot be identified as belonging to the self, and the usual Nyāya claim is that the self is the agent of cognising, while the mind