Trust not a broken staff.

Understand the thought

Meaning in plain English

Do not depend on something whose relevant support is already known to be unreliable. The broken staff pictures a failed basis for reliance, without requiring every imperfect resource to be discarded or supplying practical walking advice.

What the words are saying

The staff is meant to supply support, but its broken condition makes that function uncertain in the saying’s image. Figuratively, a plan may rely on an arrangement that has already failed in a way important to the task. A useful response checks whether it has been repaired, whether another support is available and what part can still reasonably be used. The warning should not become a permanent judgement on a person after one mistake. Nor does every flaw make an entire resource worthless. Its point is to test the relevant support before placing a demand on it again.

Everyday example

A team confirms that a previously unreliable booking system has been corrected before depending on it as the sole record for a new event.

When to use it

Use it when a known failure affects the support a plan expects to use.

Agent-assisted editorial interpretation. This explains the words; it does not by itself verify their author or earliest origin.