In Paris he often met André Breton, Marcel Duchamp, Tristan Tzara, Salvador Dalí, Luis Buñuel, Paul Éluard in the eve of the publishing of the Second Surrealist Manifesto, which promoted the illusionist representation, preventing a possible aestheticism in which the automatic method might fall.
Around this time Berni went with writer and painter Max Jacob to a lithography atelier and, thrilled by this technique, he decided to practice it.
He became fiends with philosopher Henri Lefebvre –who linked him with leftist ideas– and with poet Louis Aragon. He embraced the thesis supporting the commitment of art with revolution and with the liberation struggles which Aragon sustained. Together with him, Berni joined the Anti-imperialist Movement in which Asian, African, Latin American and French intellectuals and students took part. In these years Berni read Freud, Lautréamont, Rimbaud, Gide and Proust.
In May he exhibited a group of fifteen works at Amigos del Arte, while at the same moment, in another salon, Xul Solar realized