a man who is his own lawyer has a fool for a client

The phrase "a man who is his own lawyer has a fool for a client" is an old proverb that suggests representing oneself in legal matters is unwise or foolish. It implies that individuals who choose to act as their own attorney in a court case typically lack the expertise, objectivity, and legal knowledge necessary to effectively present their case and make wise decisions. In essence, it warns against the potential disadvantages and unfavorable outcomes that could arise from self-representation in legal proceedings.