In the early 1890s Deville gradually withdrew from formal POF membership, although his work continued to show Guesdist influences. On July 1, 1893,
George Diamandy published the first issue of ''L'Ère Nouvelle'' ("The New Era"), a "monthly for
scientific socialism". It viewed itself as both a literary and a sociological review: dedicated to promoting
naturalism and
historical materialism. It openly provoking the reading public to explore the work of
Émile Zola and attacked "reactionary" critics. It also proudly called itself "eclectic". ''L'Ère Nouvelle'' hosted articles by
Marxist thinkers from the various countries of Europe: primarily
Friedrich Engels and
Paul Lafargue, but also
Georgi Plekhanov,
Clara Zetkin,
Karl Kautsky,
Jean Jaurès, Gabriel Deville and
Jules Guesde. Deville published ''L'Etat et le Socialisme
(1893), Socialisme, révolution, internationalisme
(1893) and Principes socialistes'' (1896). His
Introduction to the abridged ''Le Capital, de Karl Marx, résumé et accompagné d'un aperçu sur le socialisme scientifique'' is a masterly summary of Marx's analysis of the process of accumulation. It was highly effective in making the arguments in Marx's lengthy work accessible to the public. On 21 June 1896 Deville was elected deputy for the first district of the
4th arrondissement of Paris in a by-election after Désiré Barodet(
fr) had resigned. He ran on an anti-Guesdist platform, and was among those vilified by the POF for their "dire spirit of personal vanity and the hunger for advantages". He ran for reelection for the second district in 1898, but was defeated and left office on 31 May 1898. Around this time
Jean Jaurès asked Deville to help him locate primary material on the
French Revolution in the parliamentary archives. Although Deville still took a theoretical interest in capitalism's economic and social problems, he had now become much closer to the independent socialists associated with Jaurès. Deville wrote
Thermidor et Directoire (1794–1799), a volume of Jaurès's
Histoire socialiste. His volume was dominated by the character of
François-Noël Babeuf (Gracchus Babeuf), the leader of the 1796 "Conspiracy of the Equals". Babeuf gave a clear statement of egalitarian principles, but was also pragmatic and willing to support the
Directory against the threat of royalist counter-revolution. In 1899 Deville supported
Alexandre Millerand's entry into the cabinet of
Pierre Waldeck-Rousseau. On 22 March 1903 Deville was elected to the fourth district in a by-election to replace Daniel Cloutier(
fr), who had died. He defeated
Maurice Barrès in the second round of voting. In the house he positioned himself with Juarès and
Aristide Briand. Deville was secretary of the Committee for Separation of the Church and the State.
Ferdinand Buisson was president of this committee and Briand was rapporteur. He was active in debates and proposed various laws. Deville became a member of the Central Committee for Research and Publication of Documents on the Economic History of the French Revolution in December 1903. In June 1905 he became a member of the Library and Archives Organization Committee. He did not run for reelection in the 1906 general elections. Deville left office on 31 May 1906. ==Later career==