He whose proposed actions are never obstructed by heat or cold, fear of attachment, prosperity or adversity, is considered wise.
He who understands quickly, listens patiently, pursues his objects with judgement, not just from (gross) desire, and spends not his breath on the affairs of others without being asked, is said to possess the foremost mark of wisdom.
He who speaks boldly, can converse on various subjects, knows the science of argumentation, possesses genius, and can interpret the meaning of what is writ in books, is reckoned as wise.
– Vidura in the Mahabharata