Self-Reliance is an essay by Ralph Waldo Emerson, published in his first collection of Essays in 1841, and the central statement of American Transcendentalism.
Its argument is that genius consists in trusting your own thought, that society is organised as a conspiracy against the individuality of every one of its members, and that consistency with your own past self is a trap rather than a virtue.
Emerson had resigned as a Unitarian minister in 1832 and spent the rest of his life as a lecturer and essayist. He was Thoreau's mentor and, in a different register, a direct influence on Nietzsche — who kept a copy and marked it heavily.