The concept of ego autonomy introduced by Hartmann and developed by Rapaport is critically examined. In view of Hartmann's modification of Freud's original position on the origin of the ego, it is believed that a more positive statement is warranted regarding the ego's constructive activities than is given by these writers. Hartmann's hypotheses of drive neutralization and secondary autonomy are discussed and criticized. Formulations by Sigmund Freud and by Anna Freud are interpreted as justifying the concept of ego autonomy. A more definite conception of the constructive functions of the ego is presented, utilizing some of the ideas of Federn, Weiss, Angyal, and Menninger.