Born the son of a Jewish merchant in Berlin, he attended the Französisches Gymnasium until he began to train as an actor and joined a traveling theatre troupe.

He also published political essays under the pseudonym Apostata in several liberal newspapers like the Berliner Tageblatt edited by Rudolf Mosse.

[citation needed] Initially a monarchist, Harden became a fierce critic of Kaiser Wilhelm II and his entourage including Philipp, Prince of Eulenburg, and General Kuno von Moltke.

In reaction, Karl Kraus, disgusted by the public display of intimate details, wrote an obituary: Maximilian Harden.

British historian A. J. P. Taylor wrote: Harden was certainly the most brilliant political writer during the reign of Wilhelm II.

In international affairs, he swung from one extreme to another: at one time a Big Navy man, later an advocate of a naval agreement.