Vivekananda did not belong to the school of thought that advises its students to keep solemn promises in supreme secrecy until they are fulfilled and manifested in the outer world. He was wont to make solemn promises openly, and then he used his volcanic concentration-power for their perfect manifestation — and he was always crowned with success.

From: Sri Chinmoy, Vivekananda: an ancient silence-heart and a modern dynamism-life - , Agni Press, 1993
Sourced from http://www.srichinmoylibrary.com/vvk-31