He who trusts a secret to his servant makes his own man his master.

Whoever knows the thing you most need kept quiet has power over you, and the arrangement of rank between you stops mattering the moment the secret changes hands. The power does not have to be used. The knowledge alone changes how you speak to that person and what you feel able to ask of them. What you hide becomes a lever, and you hand over the lever yourself.

Before confiding something delicate, ask whether you would be at ease if the person repeated it. If not, either keep it or choose someone whose interests do not run against yours.