Max Graf, and Sandor Ferenczi. In 1908, Adler presented his paper, "The aggressive instinct in life and in neurosis", at a time when Freud believed that early sexual development was the primary determinant of the making of character, with which Adler took issue. Adler proposed that the sexual and aggressive drives were "two originally separate instincts which merge later on". Freud at the time disagreed with this idea.

When Freud in 1920 proposed his dual instinct