कुसले अकुसले धम्मे, जाणइ लोगे मेहावी ॥13.1॥
The wise person knows what is good and what is harmful in the world.
Mahavira opens Chapter 13 with a deceptively simple distinction that frames everything that follows. "The wise person knows what is good and what is harmful in the world." The distinction being drawn is between two types of knowledge. The first type is the knowledge that functions as a guide to action — knowing which actions move you toward liberation and which move you away from it. This knowledge is operationally relevant; it changes how you live. The second type — which Mahavira is implicitly contrasting against the first — is knowledge that is impressive but non-operational: vast learning about scripture, mastery of ritual procedures, fluency in sacred languages, philosophical sophistication. This second type can be displayed, debated, and admired without changing how a single action is performed. Mahavira's point is not that scriptural learning is worthless; it is that learning disconnected from its moral and behavioral implications has not yet become wisdom. The wise person in this verse is specifically defined as someone whose knowledge tells them what helps and what harms. If your learning cannot answer that question in practice, something essential is missing from it.
The simple version: True knowledge tells you what helps and what harms. If your learning cannot answer that question, something essential is missing.