Related:

• A fool finds pleasure in evil conduct, but a man of understanding delights in wisdom.
  Miscellaneous Proverb...
• Do not answer a fool according to his folly, or you will be like him yourself.
  Miscellaneous Proverb...
• A fool finds no pleasure in understanding but delights in airing his own opinions.
  Miscellaneous Proverb...
• Even a fool is thought wise if he keeps silent, and discerning if he holds his tongue.
  Miscellaneous Prove...
• The prudent man looketh well to his going. -- Old Testament -- Proverbs xiv, 15
• When friends ask, there is no tomorrow. Miscellaneous Proverb
• Every man is a fool in some man's opinion. Spanish Proverb
• A man's ruin lies in his tongue. Egyptian Proverb