While in high school in 1887, together with Garabet Ibrăileanu, N. Savin, D. Moscu, and T. Cardaș, he founded the socialist Oriental literary society.
During this period, he undertook a systematic reading of Pierre-Joseph Proudhon, Karl Marx, Friedrich Engels, Max Nordau, Charles Darwin, and Herbert Spencer, as well as of Hippolyte Taine and Georg Brandes.
He contributed social criticism and theoretical articles to the socialist newspapers Critica socială and Munca, as well as to Evenimentul (also edited by Ibrăileanu).
His close friends Ibrăileanu and Sofia Nădejde published a posthumous collection of his criticism as Scrieri literare (1895).
In his work, Ionescu-Rion showed himself to be a follower and admirer of Constantin Dobrogeanu-Gherea, also displaying a close affinity with Ibrăileanu.