An old doctor, a young lawyer.

The proverb recommends choosing a doctor with many years behind them but a lawyer who is relatively young. It treats age as a different kind of advantage in each profession.

Its contrast is a rule of thumb about whom to consult, not a claim that every older doctor or younger lawyer is more capable than their peers.

Use it when discussing how people choose medical and legal advisers, especially when contrasting the value they place on experience with the value they place on youth. It can also introduce a discussion of the limits of judging professionals by age.