structural:expansion, information:extraction, stylistic:tone
Political and literary development

Gorky's reputation grew as a unique literary voice from the bottom stratum of society and as a fervent advocate of Russia's social, political, and cultural transformation. By 1899, he was openly associating with the emerging Marxist social-democratic movement, which helped make him a celebrity among both the intelligentsia and the growing numbers of "conscious" workers. At the heart of all his work was a belief in the inherent worth and potential of the human person. In his writing, he counterposed individuals, aware of their natural dignity, and inspired by energy and will, with people who succumb to the degrading conditions of life around them. Both his writings and his letters reveal a "restless man" (a frequent self-description) struggling to resolve contradictory feelings of faith and scepticism, love of life and disgust at the vulgarity and pettiness of the human world.

In 1916, Gorky said that the teachings of the ancient Jewish sage Hillel the Elder deeply influenced his life: "In my early youth I read...the words of...Hillel, if I remember rightly: 'If thou art not for thyself, who will be for thee? But if thou art for thyself alone, wherefore art thou'? The inner meaning of these words impressed me with their profound wisdom...The thought ate its way deep into my soul, and I say now with conviction: Hillel's wisdom served as a strong staff on my road, which was neither even nor easy. I believe that Jewish wisdom is more all-human and universal than any other; and this not only because of its immemorial age...but because of the powerful humaneness that saturates it, because of its high estimate of man."

He publicly opposed the Tsarist regime and was arrested many times. Gorky befriended many revolutionaries and became a personal friend of Vladimir Lenin after they met in 1902. He exposed governmental control of the press (see Matvei Golovinski affair). In 1902, Gorky was elected an honorary Academician of Literature, but Tsar Nicholas II ordered this annulled. In protest, Anton Chekhov and Vladimir Korolenko left the academy.

From 1900 to 1905, Gorky's writings became more optimistic. He became more involved in the opposition movement, for which he was again briefly imprisoned in 1901. In 1904, having severed his relationship with the Moscow Art Theatre in the wake of conflict with Vladimir Nemirovich-Danchenko, Gorky returned to Nizhny Novgorod to establish a theatre of his own. Both Konstantin Stanislavski and Savva Morozov provided financial support for the venture. Stanislavski believed that Gorky's theatre was an opportunity to develop the network of provincial theatres which he hoped would reform the art of the stage in Russia, a dream of his since the 1890s. He sent some pupils from the Art Theatre School—as well as Ioasaf Tikhomirov, who ran the school—to work there. By the autumn, however, after the censor had banned every play that the theatre proposed to stage, Gorky abandoned the project.

As a financially successful author, editor, and playwright, Gorky gave financial support to the Russian Social Democratic Labour Party (RSDLP), as well as supporting liberal appeals to the government for civil rights and social reform. The brutal shooting of workers marching to the Tsar with a petition for reform on 9 January 1905 (known as the "Bloody Sunday"), which set in motion the Revolution of 1905, seems to have pushed Gorky more decisively toward radical solutions. He became closely associated with Vladimir Lenin and Alexander Bogdanov 's Bolshevik wing of the party, with Bogdanov taking responsibility for the transfer of funds from Gorky to Vpered. It is not clear whether he ever formally joined, and his relations with Lenin and the Bolsheviks would always be rocky. His most influential writings in these years were a series of plays on social and political themes, most famously The Lower Depths (1902). While briefly imprisoned in Peter and Paul Fortress during the abortive 1905 Russian Revolution, Gorky wrote the play Children of the Sun, nominally set during an 1862 cholera epidemic, but universally understood to relate to present-day events. He was released from the prison after a European-wide campaign, which was supported by Marie Curie, Auguste Rodin and Anatole France, amongst others.

Gorky assisted the Moscow uprising of 1905, and after its suppression his apartment was raided by the Black Hundreds. He subsequently fled to Lake Saimaa, Finland. In 1906, the Bolsheviks sent him on a fund-raising trip to the United States with Ivan Narodny. When visiting the Adirondack Mountains, Gorky wrote Mother, his probably most famous novel of revolutionary conversion and struggle; despite its success and political impact, various critics and Gorky himself were harsh of the book's value as of a work of art. His experiences in the United States—which included a scandal over his travelling with his lover (the actress Maria Andreyeva) rather than his wife—deepened his contempt for the "bourgeois soul".