oneself

Oneself \One`self"\ (w[u^]n`s[e^]lf"), pron.
   A reflexive form of the indefinite pronoun one. Commonly
   written as two words, one's self.
   [1913 Webster]

         One's self (or more properly oneself), is quite a
         modern form. In Elizabethan English we find a man's
         self = one's self.                       --Morris.
   [1913 Webster]
    

34 Moby Thesaurus words for "oneself":
      I, I myself, alter, alter ego, alterum, better self, ego,
      ethical self, he, her, herself, him, himself, inner man,
      inner self, it, me, my humble self, myself, number one, other self,
      ourselves, self, she, subconscious self, subliminal self, superego,
      them, themselves, they, you, yours truly, yourself, yourselves