around 1909 he contacted sigmund freud, and in january 1910 was accepted as a member of the vienna psychoanalytic association where he gave talks on the fire as a sexual symbol and on suicides at school age. together with freud, he wrote a manuscript entitled “dreams in folklore” in 1911 which was only published in 1958, because oppenheim left the association and instead joined the school of individual psychology of alfred adler in 1911. oppenheim had an important position within the new school, and he wrote several articles in the "internationale zeitschrift für individualpsychologie".