From Notes from Lectures and Discourses of Volume 5 of The Complete Works of Swami Vivekananda
In explanation of the term Sannyâsin, the Swami in the course of one of his lectures in Boston said:
When a man has fulfilled the duties and obligations of that stage of life in which he is born, and his aspirations lead him to seek a spiritual life and to abandon altogether the worldly pursuits of possession, fame, or power, when, by the growth of insight into the nature of the world, he sees its impermanence, its strife, its misery, and the paltry nature of its prizes, and turns away from all these — then he seeks the True, the Eternal Love, the Refuge. He makes complete renunciation (Sannyâsa) of all worldly position, property, and name, and wanders forth into the world to live a life of self-sacrifice and to persistently seek spiritual knowledge, striving to excel in love and compassion and to acquire lasting insight. Gaining these pearls of wisdom by years of meditation, discipline, and inquiry, he in his turn becomes a teacher and hands on to disciples, lay or professed, who may seek them from him, all that he can of wisdom and beneficence.
A Sannyasin cannot belong to any religion, for his is a life of independent thought, which draws from all religions; his is a life of realisation, not merely of theory or belief, much less of dogma.