His father, Eduard Avenarius, a publisher from Leipzig, founded a joint subsidiary company with the Brockhaus publishing house. His mother, C*cilie n*e Geyer, was a daughter of the actor and painter Ludwig Geyer. Eduard Avenarius represented the company in Paris, where he consorted with Heinrich Heine and Richard Wagner, the latter being the stepuncle of Ferdinand Avenarius and his brother, the philosopher Richard Avenarius.
Richard Wagner
Ferdinand Avenarius