According to Ralph Waldo Emerson, why should people trust themselves?

In his essay,
"", Emerson says, "Trust thyself: every heart vibrates to that iron
string."  He says that people know themselves better than they know anyone else and that
they know themselves better than anyone else knows them, therefore, trusting oneself is a
natural off-shoot.  Emerson also contends that if a person truly gets to know himself through
introspection, then the person can rely completely on his instincts to guide him.  The catch
there is that the individual must do a great deal of introspection; a process that takes much
time and effort.  The transcendentalists, of which Emerson was a major proponent, believed that
a person's instincts were the best guide for a person, as long as the individual knew himself
completely.  Emerson contended that society wants people to think in group terms rather than in
individual terms and he felt that people were better off trusting in themselves and thinking in
individual terms.