He that communicates his secret to another makes himself that other’s slave.

Baltasar Gracián (1601–1658), a Spanish Jesuit and moralist of the Baroque era, wrote a series of terse maxims on prudence, self-command, and social strategy for life at court and in public affairs. The sentiment about secrecy reflects the high-stakes culture of patronage and intrigue in 17th‑century Spain, where reputation and favor could turn on a single disclosure. In Gracián’s aphoristic works—especially his handbook of worldly wisdom—he repeatedly warns that information is power and that self-mastery includes mastery of one’s tongue. The line encapsulates his broader counsel to be cautious, guarded, and strategically silent in dealings with others.

Gracián argues that revealing a secret transfers leverage to the listener: once someone else holds your confidential knowledge, you become dependent on their discretion and goodwill. “Slave” is rhetorical but pointed—your freedom of action narrows because you must now manage the other person’s potential to expose, exploit, or bargain with what you shared. The maxim also implies a moral psychology: secrecy is a form of self-possession, while indiscretion is a surrender of control. In Gracián’s pragmatic ethic, trust may be admirable, but in competitive social worlds it is risky; prudence requires limiting what others can use against you.

“He who communicates his secret to another makes himself that other’s slave.”