"Great is the tenacity with which man clings to the senses. Yet, however substantial he may think the external world in which he lives and moves, there comes a time in the lives of individuals and of races when, involuntarily, they ask, "Is this real?" To the person who never finds a moment to question the credentials of his senses, whose every moment is occupied with some sort of sense-enjoyment - even to him death comes, and he also is compelled to ask, "Is this real?" Religion begins with this question and ends with its answer."

- Swami Vivekananda, "The Real Nature of Man" (The Real and The Apparent Man, June 21, 1896, Royal Institute of Painters, London), Jnana Yoga, Complete Works: Vol 2