In this quote, Plato is recommending that cunning is a bad replacement for knowledge. He is indicating that cunning is a shallow imitation of wisdom, and that it is not a real type of intelligence. Plato is recommending that shrewd is a type of trickery and deceptiveness, which it is not a reliable source of understanding. He is suggesting that knowledge is a far more valuable kind of intelligence, and that it is the only method to truly understand the world. Plato is suggesting that knowledge is the only method to gain true understanding and understanding, which cunning is a poor substitute. He is implying that wisdom is the only way to acquire real insight and understanding, which cunning is a shallow replica of it.
"Raising children is an incredibly hard and risky business in which no cumulative wisdom is gained: each generation repeats the mistakes the previous one made"
"The man who makes everything that leads to happiness depends upon himself, and not upon other men, has adopted the very best plan for living happily. This is the man of moderation, the man of manly character and of wisdom"